Magma Cum Laude

The volcano Gatekeeper

2010-11-06T20:39:00.000-04:00

One of the sad - but not unexpected - stories to come from the eruption at Mount Merapi concerns the death of the "Gatekeeper" of the volcano, Mbah Marijan. Marijan was mentioned in a 2008 National Geographic article, "The Gods Must Be Restless", that I blogged about a long time ago - and that has turned out to be depressingly prophetic...

Want to read the rest of this post? Go to Magma Cum Laude's new home at the AGU Blogosphere - and remember to update your links and RSS feeds! This will be the last article crossposted to this site; after today, you will need to go to the new AGU page to follow the blog.

Support volcano monitoring and future volcanologists

2010-11-03T10:32:00.000-04:00

Santiaguito Volcano Observatory Fundraiser

It's been a while since I wrote about this, and it's definitely time for an update. If you're new to Magma Cum Laude, or just haven't visited the site for a while, you'll notice that there's a "Donate to Santiaguito" tab on the top of the page. Clicking there will help you learn a bit more about a fundraising effort I helped start earlier this year for the Santiaguito Volcano Observatory in Guatemala. For my field research, I spent most of my time either at the Observatory or working with its staff, and realized that although they're in a prime location to collect valuable data about an active volcano, they have very little of the resources and equipment they need...

Want to read more about Earth science fundraising? Check out the rest of this post at Magma Cum Laude's new home on the AGU Blogosphere. Don't forget to update your bookmarks and RSS feeds!

Happy Halloween!

2010-10-31T16:07:00.002-04:00

Instead of candy, why not try some nutritious squash?

Geological Frightfest: The Monolith Monsters

2010-10-30T21:57:00.000-04:00

Lee Allison at Arizona Geology deserves credit for inspiring the last movie in the Frightfest series - in his post from June about the Piranha 3D movie, he also mentioned The Monolith Monsters. Again, it's another 1950s movie I haven't had the chance to see, but I'll definitely have to remedy that if I can...guess what's next on the Netflix queue? With a title like that, though, I couldn't resist looking it up. And boy, this one is a doozy. Here's the IMDB summary:

A strange black meteor crashes near the town of San Angelo and litters the countryside with fragments. When a storm exposes these fragments to water, they grow into skyscraper-sized monoliths which then topple and shatter into thousands of pieces that grow into monoliths themselves and repeat the process. Any humans in the way are crushed or turned into human statues. The citizens of San Angelo desperately try to save themselves and the world from the spreading doom.

Wikipedia also expands on this with some dirt on some of the main characters, who happen to be geologists (though apparently not very good at on-the-fly rock identification):

In the desert region of San Angelo, California, geologist Ben Gilbert brings a strange black rock back to his office, where he and bored local reporter Martin Cochrane examine it but fail to determine its origin. That night, a strong wind blows a bottle of water over onto the rock, which begins to bubble and smolder. The next day, the head of the geological office, Dave Miller, returns to town from a business trip and finds the office destroyed by a huge growth of black rock and Ben dead, in a rock-hard, apparently petrified state.

Things certainly go downhill from there. The rocks spread via the pockets of students on a geology field trip, and pretty soon folks are turning into stone left and right. Not only are the rocks sucking silica out of people, but coming into contact with water allows them to grow and multiply. (Since humans only contain trace amounts of silica, these are obviously not very smart rocks.) The geologists eventually figure out that these are evil outer space rocks, and that salt water (???) will stop their growth. I won't tell you the thrilling conclusion, although it's there in the Wikipedia summary (spoiler alert!) if you want to read it.

This movie is impressive not only for the fact that it has evil space rocks sucking the silica out of people, but for its fantastically corny (and geologically incorrect) dialog. Here are a few gems:

"The desert's full of things that don't belong. Take the salt here. Used to be an ocean bed. Now that ocean knew that the middle of a desert was a pretty silly place for it to be, so it just dried up and went away."

"You've got to remember, Dave, when this hit our atmosphere, it burned at such a fantastic temperature, that its metal-bearing compounds could have been altered - left ready to activate, to grow!"

"From infinity they come. Meteors! Another strange calling card from the limitless regions of space - its substance unknown, its secrets unexplored. The meteor lies dormant in the night - waiting!"

Okay, the last one wasn't wrong, but I just had a mental image of a lurking meteor(ite), and it looked something like this:

Watch out, folks. Those space rocks will get you.

Geological Frightfest: El Monstruo de los Volcanes

2010-10-29T20:48:00.000-04:00

Tonight's post will be a short one, because it's Friday and I just spent the last hour carving a pumpkin. This Frightfest offering comes via the suggestion of a devoted reader (thanks, Mom!), and I had to post it, even though I can't find out a lot about the movie. This is the best I could dig up for El Monstruo de los Volcanes: A yeti-like creature with the power to hypnotize its victims stalks the slopes of Mount Popocatepetl, attacking construction workers who are building an inclined railway on the volcano.

Yep, a 1962 horror movie about a volcano yeti. I don't think I can add much to that. (Here's a Spanish website with a short blurb about the movie, for those of you who can read it. Oh, and funicular is another word for an inclined railway, if you get stuck translating it.)

On the volcanic side of things, Volcan Popocatepetl (the name means "smoking mountain" in the Aztec language) is a large stratovolcano about 70 km SE of Mexico City. Its most recent eruption began in January 2005 with a series of phreatic explosions, and has continued since with explosive eruptions of ash and the extrusion of a lava dome. (Check out the GVP's monthly and weekly summaries for more details!)

Geological Frightfest: Fantasia

2010-10-28T22:22:00.000-04:00

http://en.wikipedia.org/wiki/File:Fantasia-poster-1940.jpg

All right, so Fantasia probably isn't the first thing you think of when the topics of horror movies or geology come up (and I'm not talking about the whole movie, so I'm cheating a bit with this one). But I am talking about the excellent Night on Bald Mountain sequence, where the animators set Modest Mussorgsky's composition of the same name.

I loved Fantasia as a child, and still do - but I have to admit that this sequence was pretty darn scary. (Disney did include it years later in their Halloween Treat TV special, after all - remember that? I used to watch it every year.) Anyway, a quick summary of the animation: In the dead of night, the huge, craggy mountain looming over a small European town becomes the haunt of a huge winged demon and the gathering place of ghosts, ghouls, devils, witches, and all manner of fell creatures. They proceed to have a fiery revel, but are forced back to their lairs by the tolling of church bells.

While the animation is truly imaginative, it's the music that brings me to a geological reference - and the setting that inspired Mussorgsky's title. (Or, rather, Rimsky Korsakov's orchestral arrangement of Mussorgsky's original tone poem St. John's Night on the Bare Mountain.) A bald or bare mountain, in East Slavic (and especially Ukranian) mythology, is a place where witches and other evil creatures gather for their Sabbath. In Ukranian, the term is lysa hora, which is also the name given to many "bald" mountains in Ukraine and Poland. One of the most famous is the Lysa Hora in Kiev, which was supposedly the site of some of the largest witches' gatherings.

This got me to wondering: Why would these hills be bare in the first place? Perhaps there's some geology at work here. In the Blue Ridge mountains, for example, there are a number of spots where the mountaintops are rocky and relatively bare of trees; Old Rag Mountain is topped with granite, and Blackrock Summit with well-cemented quartz sandstone. I was able to find this map of the geology of the USSR (from 1944), but I can't read or type Cyrillic, so it's not much help. Ole Nielsen has a post on kimberlites in the Ukranian Shield which mentions granites, an excellent candidate rock type for bare-topped hills, and possibly what one might find on the summit of a lysa hora. Why would these rocks form bare summits? Well, granite can take an extremely long time to form enough soil to support plant life, especially if it's exposed to transport processes by being at the top of a mountain - and while a sandstone might weather more easily, it needs some organic inputs before it will form anything but...well, sand.

So, it's a good bet that the impressive winged demon in the Fantasia sequence is clinging to something granitic, although the craggy peak in the film is showing just a teensy bit of vertical exaggeration, if you ask me.

The move has finally happened!

2010-10-28T17:50:00.000-04:00

Magma Cum Laude has officially moved to its new home at the AGU Blogosphere, http://blogs.agu.org/magmacumlaude/ - you know, that thing that a bunch of us have been hinting at for a while now. But don't fret; I'll be cross-posting on this site for a little while in case you forget to update your bookmarks and RSS feeds. (By the way, update your bookmarks and RSS feeds!) All the old posts from this site will be archived at the new blog as well.

It's been a long time coming, but I'm happy to be making the move to a different blogging platform, and thrilled to be enjoying the company of such excellent geobloggers. (Go to http://blogs.agu.org to see the full lineup!)

Spooky Deskcrop - Accretionary Wedge #28

2010-10-28T09:55:00.000-04:00

The latest Accretionary Wedge is being hosted at Research at a Snail's Pace by Matt Kuchta...and the theme is deskcrops (spooky if possible, for Halloween!) My favorite deskcrop is one that I acquired fairly recently on Montserrat, from the February 2010 dome collapse deposits of the Soufriere Hills volcano. This isn't a particularly small sample, but it was one of the easiest to collect - already pre-rounded, and of course it didn't add much mass to my luggage, because it's a chunk of pumice! (Sorry for the color variations in the next few photos - I was using the cheap camera and the color balance always goes wonky on that one.)

What I find really spooky about this particular sample is that it has a story to tell, recorded in that big black mark. It's suspiciously femur-shaped.

Femur figure courtesy of Gray's Anatomy, via Wikimedia Commons.

But don't worry! That mark has nothing to do with human remains (no one was killed in that dome collapse, and I would never disturb remains if I came across them). It's actually a scorch mark from a tree limb that I found the pumice block resting against. Remember this photo?

When this pumice flow lobe came into contact with the vegetation in this area, it was hot enough to scorch it, and in a lot of cases the pumice clasts are still resting on the tree limbs they burned. This particular piece of pumice records the shape of one of those limbs.The scorch mark itself is pretty cool - it's sooty from the carbonized wood, but it also has little patches of remelted glass.

And, for all you mineralogists out there, here's a really nifty little shattered hornblende phenocryst. (The predominant composition of the eruptive products at Soufriere Hills is andesitic, so there are also quite a few large plagioclase phenocrysts in there as well.)

Scorching!

Geological Frightfest: The Mole People

2010-10-27T20:18:00.001-04:00

http://upload.wikimedia.org/wikipedia/en/8/8e/Mole_People.jpg

I thought I'd go with a classic film for today's edition of Geological Frightfest, because the premise of The Mole People is just so interesting. It's not actually one I've seen, and I know a lot of younger readers probably won't have ventured into the realm of 1950s horror, so here's a bit of summary from Wikipedia:

"The film begins with a narration by Dr. Frank Baxter, an English professor at the University of Southern California, explaining the premise of the movie and its basis in reality. He briefly discusses the hollow earth theories of John Symmes and Cyrus Teed among others, and says that the movie is a fictionalized representation of this unorthodox point-of-view.

"In this movie, archaeologists Dr. Roger Bentley and Dr. Jud Bellamin stumble upon a race of Sumerian albinos living deep under the Earth. They keep mutant humanoid mole men as their slaves to harvest mushrooms, their primary food source, since they can grow without sunlight. The Sumerian albinos' ancestors moved into the subterranean after the cataclysmic floods in ancient Mesopotamia."

The mention of the "Hollow Earth" idea was what caught my eye. In college, I took a freshman seminar called "Applied Pseudoscience", where we discussed logical fallacies and pseudoscience topics like this theory; our textbook was the venerable Fads and Fallacies in the Name of Science by Martin Gardner (1952), and that's where I turn whenever hollow Earth ideas get mentioned. Captain John Cleves Symmes first came up with the idea of a hollow Earth in 1818, when he suggested that the Earth was made up of five concentric spheres, both sides of which sustained plant and animal life, with huge openings at the poles. (He campaigned for years trying to get the U.S. Congress to fund an expedition to the North Pole, without success, and died in 1829 from the strain of constant campaigning.) Cyrus Reed Teed, another 19th century American, tried to advance an even more bizarre idea - that we were living on the inside of a hollow sphere, with the sun, moon, planets and stars inside the hollow and nothingness outside. (According to this idea, the internal sun is half light and half dark and rotates, thus producing day and night. If you think the sun is a light bulb, that sort of makes sense; it's when he starts talking about planets as "spheres of substance aggregated through the impact of afferent and efferent fluxions of essence" that I get lost.)

The idea had been mentioned even earlier than the 19th century, however. Edmund Halley published an essay in 1692 describing an Earth with a shell 500 miles thick, two inner shells the size of Mars and Venus, and a solid inner sphere the size of Mercury (all of which should be capable of bearing life). A particularly brilliant display of the aurora in 1716 prompted him to suggest that the lights were caused by glowing gas escaping from thin spots in the outer sphere at the poles. Doubtless there were many people before Halley who came up with similar ideas, perhaps related to the idea of an underworld - although they probably never came up with something as odd as mushroom-harvesting mutant mole men!

PS - It looks like you can read a pretty good chunk of Fads and Fallacies via Google Books, and I highly recommend it; it's a pretty funny book and covers a lot of pseudoscientific topics, although it can get a bit dense in parts.

Geological Frightfest: Jurassic Park

2010-10-26T21:05:00.001-04:00

http://upload.wikimedia.org/wikipedia/en/e/e7/Jurassic_Park_poster.jpg

Okay, given the super-gory, blood-soaked grossness that today's monster movies seem to be embracing, Jurassic Park is pretty tame. Tasteful, even, when people get eaten by dinosaurs. But let me tell you, when it came out in 1993, that was a pretty darn scary movie. (I remember seeing it as an eight-year-old, and I can't remember a movie since that's actually frightened me out of my seat and two or three feet vertically above it.) I'd been on the Dinosaur ride at Disney World, and these were certainly far beyond the jerky, obviously mechanical critters on display there.

But aside from freaking out an eight-year-old who then dragged her parents to the National Museum of Natural History's Dinosaur Hall a whole lot more often, Jurassic Park opened up a whole can of exciting - and frightening! - possibilities about paleontology to the general public. Were dinosaurs really that vicious? What if we could recreate them using DNA recovered from fossils? Were paleontologists already trying to do that? And if it was possible, could we control our creations - before they decided to eat us, that is? (Frankly, I always thought that they could have solved that problem by not creating carnivores in the first place, but that would have made for a much less exciting plot. Nobody wants to see a movie where the main danger from the monster is accidentally getting stepped on.)

There was a lot of discussion of the question of recovering viable, ancient DNA (although not necessarily from amber) in the 90s, but it seems pretty clear that even if there was DNA preserved, it wasn't likely to be complete and undamaged. Even the 'mummified' hadrosaur discovered in 2007, which was extremely well-preserved, didn't net anyone a full genome. (For a discussion of why it would be tough to make a dinosaur even if we did have all the DNA we needed, have a look at the University of California Museum of Paleontology's Dinobuzz page - it's lacking some references, but I suspect it's not meant to read like a journal article.)

But questions of ability aside, which dinosaur would we make if we actually could - and what would we do with it? Assuming that we could adjust its immune system to deal with today's diseases and find it something to eat, there's no telling how it would react to its environment or its creators. (If we made an herbivore, which tended to be large, would it just act like a big cow? Would a carnivore try to eat people, or would it be happy with goat?) Like the scene in The Lost World where the t. rex gets loose in San Diego, a recreated dinosaur could cause considerable problems were it to escape from its handlers. (Sir Arthur Conan Doyle thought of this long before Michael Crichton ever did, by the way - although a pterosaur is a flying reptile and not a dinosaur.) And what about the dinosaur? Assuming that we were somehow able to allow it to grow up free of human influences, wouldn't it be pretty scary for the dinosaur to have to deal with a modern world?

I think the scientific, ethical, and societal tangles that could be involved in recreating a dinosaur are plenty frightening - before you even get to the toothy, clawed, wants-to-eat-you part. (And no, I was not traumatized by seeing Jurassic Park when I was eight - if anything, it helped get me to the point where I could blog about it!)

Geological Frightfest: Tremors

2010-10-25T20:41:00.002-04:00

Halloween is pretty much my favorite holiday - when else can I show up at school in costume? - and I've decided to resurrect the theme of geology in the movies for a Halloween series this week. To start us off, I'll turn to that classic geologic monster movie: Tremors.

http://en.wikipedia.org/wiki/File:Tremorsposter.jpg

Tremors often comes up when lists of geology-themed movies are mentioned. Not only does it feature hungry subterranean critters, and a visiting seismologist, but at one point the heroes of the film are actually protected from the monsters by rocks. (Apparently tunneling through unconsolidated sediments is pretty easy, but granite boulders present a bit of a problem if you don't have drill bits for teeth.) There's also an appearance by Reba McEntire, for you music fans.

The movie is supposedly set in the Nevada desert, but a little research shows that it was actually filmed in Lone Pine and Olancha, California, in Owens Valley just west of Death Valley National Park. The California State Geologic Map indicates that the area is mainly Mesozoic metavolcanic and plutonic rocks, with Quaternary sediments making up the valley fill. In case that wasn't exciting enough, the Owens Valley Fault Zone cuts right through the area. (Garry Hayes of Geotripper has featured Owens Valley in a number of great posts - including one about some real tremors in the area!)

One thing that always bothered me about this movie was the "graboid" wormy things and how fast they were able to burrow through the ground. They don't appear to have any means of locomotion other than wriggling and grabbing things with their mouths, but they somehow manage to chase down some very panicked humans. (According to this "Graboid 101" website, they have skin covered with "movement hooks" that help pull them through the ground and that their large jaws enable them to "dig through the land at high speed", but I'm not buying it.) At a top speed of 15-20 mph (estimated here), these critters would far outstrip the top speed of an earthworm of the same scale. (To do some rough, totally gratuitous math: This paper estimates that a vigorous earthworm has a top speed of 10 mm/s, or 0.022 mph; assuming that a reasonable earthworm length is ~ 3 inches, scaling up to a 30-foot earthworm would still only get you a top speed of ~2.5 mph. Not even fast enough to catch a walking human!) Not to mention that this wouldn't even account for variations in the consolidation of sediments or soil, having to detour around the odd buried boulder, etc.

So while this classic movie spawned three sequals and a 2003 TV series, you shouldn't be worried about tremors of the graboid variety while visiting the Owens Valley - but watch out for earthquakes!

A few more tweaks until the new location is ready...

2010-10-24T20:03:00.003-04:00

...and the new AGU Blogosphere opens. In the meantime, I'll be revving up for Halloween with some geologically frightful topics.

Sorry for leaving you all hanging! I've been told that we'll have the bugs worked out sometime this week, and will hopefully be ready to show off the new blog network soon.

Reflecting on Earth science perceptions

2010-10-13T19:28:00.000-04:00

It's Earth Science Week again - this time with an energetic twist. Volcanology and energy are certainly linked in the geothermal realm, but I'm going to skip that discussion and discuss an article I found recently. It's called "United States earth sciences, status, and future: How bad, how good?"

The article takes a step back from the process of doing earth science and looks at its situation as a whole, and what we can (and should) be doing to help improve the public's perception of our field. (That's what Earth Science Week is all about - good outreach! - so I think it's definitely a relevant topic for a post this week.)

I'll start you off with a quote:

"In terms of public perception, however, earth scientists appear to come off rather badly, in spite of the fact that the nature of the Earth and the societal importance of mineral and energy resources, geologic hazards, and biological evolution are familiar concepts to the public. Everyone 'knows' what a physicist, chemist, or mathematician does (really?), possibly because the subjects are universally offered in secondary schools. Astronomy, however, seems to be more recognizable to the lay public than is geology, in spite of the more abstruse nature of the former, and neither science is generally taught in high school. Perhaps another reason for the lack of familiarity with geology stems from its remarkable diversity. Our field is almost unique among the sciences in being dependent on, and a blend of, all of the primary sciences and many purely geologic specializations as well."

This is certainly true. Considering that things like fossil fuels, climate change, earthquakes, eruptions, tsunamis, and the like are in the news almost every day, it's amazing to see how little people seem to know about the science behind the topics. A lot of the news seems to be about earth scientists dealing with ignorance about the process, implications and impacts of their work (like the Italian seismologists who were charged with manslaughter for not predicting the Aquila earthquake, or the climate scientist at the University of Virginia who's being hounded by the state attorney general, or the government trying to keep petroleum geologists from talking about the worst case scenarios of the BP oil spill). And I think it stems from a basic lack of understanding of Earth science, as the quote describes.

Know the interesting thing about this article? It was an address by W.G. Ernst, a retiring President of the Geological Society of America...and it was given in 1986.

The same problems we have with public perceptions of Earth science today were happening almost a quarter of a century ago. Almost before I was born, in fact. So why are we still dealing with this lack of comprehension of and respect for the Earth sciences? Shouldn't we have managed to open the public's eyes to the wonders of our field by now?

There's no simple answer to those questions. We are always in the process of trying to do improve the public's perception of Earth science - through outlets like Earth Science Week, and blogging, and outreach from professional organizations. But there also seems to be a problem with getting people involved in Earth science from the start. On the whole, it's simply not seen as an integral part of K-12 science curricula. As of 2007, there were only two states (Kentucky and North Carolina) that require an Earth science to graduate from high school, and fewer than a dozen others that integrate it into required courses. This means that a student's only exposure to the Earth sciences might come at the college level, and quite possibly as a course taken only to fulfill a science requirement. One of the American Geological Institute's Geoscience Workforce studies indicated that incoming college students perceived geology majors to be low in prestige, low in difficulty, and low-paying relative to majors like physics, chemistry, and biology. Those students didn't have a very good view of Earth science before they even had a chance to experience it. Consequently, they go on into their adult lives without a good working knowledge of the world around them, and no real way to evaluate the validity and value of what they later hear through mainstream media.

It's not all gloom and doom. Federal funding for Earth science research has more than doubled since 1986, and geoscience enrollments increased 8% in the 2008-2009 school year (a jump attributed to increased interest in energy and environmental issues). Salaries for Earth scientists have been increasing steadily for the past decade. There's a lot to find attractive about Earth science - but we need to keep selling it! Which brings me back to outreach of any kind. We as Earth scientists (and Earth science enthusiasts) need to keep telling everyone that yes, we are real scientists who do important, useful work. We work hard to get our degrees, and earn educations that are unparalleled in their breadth and depth of study. And we have fun doing it! Earth science is fascinating, and whether it's by trying to attract new grad students to your department, or get elementary school kids excited about rocks, or show off for thousands of people at a science expo, it's immensely important to never stop supporting our science. So however you do it, get out there and fulfill the spirit of Earth Science Week!

References:

Ernst, W.G. (1987). United States earth sciences, status and future: How bad, how good? Geological Society of America Bulletin, 99 (1)

A whole bunch of news

2010-10-13T09:42:00.000-04:00

I've been neglecting my posting lately because of our department move, but here's a little housecleaning (and there'll be a real post later today):

It's Earth Science Week! This year's theme is "Exploring Energy", and there's a lot going on - maybe even something in your area, which you can check on the "Events In Your Area" page. There are also contests to enter (including a photography contest that's open to anyone).

Can't find an event in your area, or don't know how to get involved in an energy-related activity?Consider an alternate - helping students and classrooms in need! Anne Jefferson and Chris Rowan over at Highly Allocthonous are hosting their yearly Earth Science DonorsChoose Challenge to raise money in support of low-income classrooms. You can read about earth science projects teachers are hoping to get their students involved in, and donate any amount of money to help purchase equipment and learning materials! (All the money will go directly to the project, and it's often matched by corporate sponsors. We're also in a friendly competition with other science bloggers, so let's show them that earth science folks really rock!)

You may have seen the announcements in other places, and I've hinted at this without giving details, so here's mine: Magma Cum Laude will be joining a number of other earth science bloggers on a new AGU blogging network! It looks like the move will be happening sometime next week. I'm really excited to be joining a group of excellent geobloggers, including Callan Bentley of Mountain Beltway, Dave Petley of Dave's Landslide Blog, and Ryan Anderson of The Martian Chronicles. I've seen some of the preliminary pages for the network, and I have to say it looks pretty slick - the move will involve a few cosmetic changes to the look of this blog, but I think they're going to turn out great. I'll cross-post to this site for a while, and remind you to update your links, once the move happens.

Another update & contacting info

2010-10-06T08:58:00.002-04:00

I know, silence on the blog is boring...

My department is in the middle of moving to another building, so I'm probably not going to be blogging until next week. And the move for the blog is still in the works, so hang in there! I'll be back to normal operations soon.

And, just a brief note for folks who've been contacting me lately:

Thanks for writing! I love getting messages, especially if I can help you out with a geological conundrum. I would appreciate it, though, if you would try to send them to me at the email address listed in my contact info (magmacumlaude at gmail dot com). Messages left in the comments don't come to my attention as quickly, and I'd rather keep comments related to the post that they're associated with. (Questions via Twitter are fine, as long as they're short or include an email that I can write back to.)

Thanks bunches!

*PS* I noticed that Blogger didn't seem to be displaying my email properly for some reason. Sorry if it wasn't available! I've fixed it and it should show up on my profile now.

Guess this means it's columnar jointing week

2010-09-29T10:22:00.000-04:00

Well, since everyone else is getting in on the columnar jointing meme/festival/whatever, I suppose I could throw a few photos out there...

Columns in an ignimbrite on the east side of Santa Maria volcano in Guatemala. (A drive-by, unfortunately. I would have loved a close-up look at these!)

Some of the oldest volcanics in the Vulsini volcanic district, Italy: a jointed trachyte from the Bolsena caldera complex. (The tree at the top of the cliff is about 3 m tall.) This is one of my favorite photos, because you can see multiple cooling sets divided by fractures - and it really emphasizes how columns form from inward-directed cooling.

Willow Mountain, Terlingua, Texas (near Big Bend). Beautiful columnar jointing throughout. (No scale on this one, but I'd say it's about 200 meters from top to base.)

And, finally, an actual example of columnar jointing in basalt, which is probably much more common than jointing in an any of the other stuff I've mentioned: a lava flow near St. George, Utah. (Wish I could figure out where, but Google Earth isn't helping today. Has anyone seen this abandoned water tank?)

Perhaps we should submit a request for a Columnar Jointing Week to someone in Washington. As far as I can tell, we're sadly lacking in geological observances anyway...

Upcoming changes

2010-09-28T12:34:00.000-04:00

Magma Cum Laude will be moving to a new location soon - more details on that when it happens! In the meantime, posting will go on here (and I'll try and cross-post if I can). Stand by for new developments...

"If we knew what we were doing, it wouldn't be called research"

2010-09-27T09:13:00.000-04:00

I talk a lot about my experiences with volcanoes and molten lava and such, but if I want to talk about my most important geological experience overall, I have to skip my volcanological career entirely and go back to the very first field course I ever took. (I mention it a lot; it was a 3 1/2 week trip to the Colorado Plateau, which is an excellent place for a crash course in field work.) We were in Utah, just outside of Capitol Reef and a few miles away from what was later to become my undergraduate thesis field area, in a little campground outside of Bicknell. Sunglow Campground was aptly named; at the end of the day the red rocks surrounding us seemed to light up as the sun was setting.

If I'm remembering correctly, this was our first real mapping assignment. I, having had no classes in mineralogy, petrology, structure, or mapping, was working with some of the older students. At this point, I'd managed to pick up basic Brunton skills and was reasonably certain I could tell sandstone from limestone. I was still pretty nervous about the assignment, since at that point I was still a bit of a perfectionist (left over from high school, I guess).

We spent the entire day climbing over rocks, gazing at outcrops from high spots, breaking off hand samples, squinting through our hand lenses. And by the end of the day, we still hadn't managed to cover the whole area. I was excited when we found what I guessed was volcanic ash right next to a pretty obvious fault, but mainly because I could actually stand on the thing and say "this is a fault". Beyond that, I was definitely having trouble putting lines and color on our map. Looking back at my field notes, I know I didn't get as detailed as I could have, mostly because I didn't really know what was important to write down. I felt like I should have been able to figure out field relations and rock types by that point on the trip.

I was completely frustrated with myself and the assignment by the end of the day, especially when it became apparent that we'd neglected to investigate a few of the units properly and left one completely off the map. Once we'd turned in our assignments, however, and were sitting around the campfire toasting food and joking, I realized something important: that I had expected myself to come up with all the answers even when I was still developing the tools I needed to find them. There was no way I was going to complete the assignment perfectly. And that was okay, because I was still learning. And that's something I've had to remind myself of all the time, especially when I get frustrated or upset over something: I'm still learning. I'll still be learning when it's time to retire - and I'll still be learning after that.

As a freshman, I may have been bright enough that my advisor invited me to come on a trip that was normally restricted to upperclassmen, but I should also have been bright enough to realize my own limitations. That was one of the best things I learned on that trip, and one that's helped me immensely since. If I can take a step back from whatever frustrating problem I'm dealing with at the moment, I can figure out what I tools and knowledge I need to acquire to solve it. That process may be slow and frustrating itself, but it's much better than thinking I know everything (and then finding out, usually in embarrassing ways, that I'm wrong). Come to think of it, this is a great way to look at life in general, not just geology.

Distinguishing deposits from andesitic eruptions

2010-09-20T10:14:00.000-04:00

Telling apart different kinds of deposits associated with volcanic eruptions isn't always easy. There are a lot of factors that can affect their appearance: the location and type of eruption, the magma/lava type, where they're emplaced, etc. On Montserrat, volcanologists are lucky to have both ancient and modern deposits; they can look at what's currently being erupted and compare it to the older volcanics on the island. We did quite a bit of this on our field trip, and one of our assignments was to summarize the characteristics of andesitic eruption deposits on Montserrat. (I emphasized that because the characteristics we saw are not necessarily going to be the same for all volcanic eruptions, or even for all andesitic eruptions. I've tried to generalize a bit, but apply these cautiously if you're going into the field to look at other volcanic deposits; things may look very different in your field area.)

Block and ash flows are a kind of pyroclastic density current. "Pyroclastic flow" is a kind of catchall term, but there are more specific ones that better describe the makeup of one of these currents. "Block and ash flow" implies that the flow is composed of blocks (either of denser lava or pumice or both) and ash; "pumice flow" means that the contents are mainly pumice and ash, "ash flow" that there are few blocks and mostly ash in the current.

Faint reverse grading in a block and ash flow deposit at Old Road Bay

Block and ash flows contain a range of clast sizes from mm-sized ash to m-scale boulders. The clasts are usually somewhat angular and tend to be a combination of lithics (lava) and pumice. The matrix of these deposits (what larger clasts are embedded in) is generally ashy and may be crystal-rich. The deposit may be clast or matrix supported (which describes whether there is enough matrix that the clasts are not touching) and poorly sorted (clasts are not separated by size). Oxidation and alteration of clasts as well as fractured blocks (including radially jointed clasts) may occur if the flow is deposited into water and cools quickly. Sometimes you can see grading in the deposits (i.e., a change from small to large clasts, or the reverse), which has to do with the energy of the pyroclastic current and the conditions under which clasts are being deposited from it.

Pointing out matrix in a deposit on the side of the Belham River Valley

Debris avalanches form from older volcanic material that's unstable enough to collapse, either because of erosion or alteration or both. They form "hummocky" deposits that are very obvious in aerial photos, but in cross section they're also fairly easy to identify.

Panorama of a debris avalanche deposit near Jack Boy Hill. Different colors mark chunks of preserved stratigraphy.

Debris avalanche deposits contain mm to m sized clasts (or larger), as well as chunks of material from older deposits that retain their original stratigraphy. These clasts and chunks are poorly sorted, and rounded to angular in shape. Clast compositions are almost always mixed, and the matrix is often clayey and highly altered. Jigsaw jointing is apparent in individual clasts, with clast fragments separated by matrix material but orientation with respect to neighboring clasts preserved. Clasts or deposit blocks may be "smeared" out into trains or show internal faulting.

A "jigsaw" fractured block in a debris avalanche deposit

Lahars form when water mixes with volcanic material and flows downslope. These can have the consistency of soup to concrete, and they're a major concern even when a volcano isn't erupting (especially if the volcano is located in a tropical area that gets lots of rain.)

House buried in lahar deposits in the Belham River Valley

Clasts in a lahar deposit range from mm to multi-meter size. They are matrix supported, poorly sorted, and often contain clay or silt in the matrix. The clast shapes vary from rounded to angular and may be either monolithologic (all one rock type) or mixed rock types, depending on the source material. Sometimes the deposits show bedding features such as cross-bedding. There is one absolutely diagnostic feature for lahars: preserved voids where bubbles of air were trapped in the matrix mud. The voids are spherical and usually pretty tiny, but they don't form in pyroclastic currents. (The lack of these voids does not, however, mean that a deposit is not a lahar, so this feature is only useful if it's present.)

Cross-section of a fairly recent lahar deposit. There's not much in the way of sorting or grading here.

A fourth type of pyroclastic current, called a surge, also shows up on Montserrat, but they're not often preserved because they consist of a blast of ash and hot gases (sometimes derived from block and ash flows), and they leave very thin deposits. I don't have any good photos of them, but they tend to be fine-grained (mm to cm sized clasts at the most), and sometimes show cross-stratification. It's rare that they're preserved, especially in a tropical environment, because the fine material washes away very easily.

A question of time

2010-09-14T16:29:00.000-04:00

*Note: Having been temporarily flattened by my yearly fall cold, I'm putting up a non-geology post that I was working on earlier this month and have just enough energy to finish now. I'll make it back to talking about andesitic eruption deposits just as soon as I emerge from the haze of cold drugs.

'Tis the season for the arrival of new grad students (geology and otherwise), and 'tis also time to talk about time. As in, time management - possibly one of the most important skills a grad can have (or develop).

You've heard it a lot of other places, but I'll repeat it here as well: Graduate school isn't like undergraduate, unless you were part of a crazy tough undergrad department. You're much more responsible for yourself, including how you portion out your time between classes, research, work (if you happen to be a TA), and downtime. I treat it as a job, because that's what it should be. And it's really, really important to know how much time to devote to the different parts of your job - and when to take a break.

Classes will be important, but unlike undergrad, they're not the biggest part of your life. Most grad programs will expect you to maintain a certain GPA of to remain in the program, but you shouldn't be working yourself to death over your classes. Eventually, you won't be taking as many (or any at all), and if you're not used to working on things other than classwork, it will be harder to adjust. Pace yourself if you can - sometimes you can put off a class that's not essential to your research.

Likewise, if you're TAing, remember that the teaching experience is useful - and if you plan to be a professor someday, it may be some of your only training - but that research is your primary mission. Put in the work that you need to, but don't get sucked into agonizing over grading or class preparation. Ask for help if you need it, from your professor or the other TAs. Don't get too emotionally invested in it; not every student is going to like you or your teaching style (or their grades).

Research should be the main focus of your time in grad school. Even if you don't have a solid idea of what you want to work on when you come in, start by doing as much reading as possible (without frying your brain). Use your class projects to help develop (and answer!) research questions. Set daily, weekly and monthly goals for yourself, and keep track of things like conference deadlines and committee meeting dates (they're good things to schedule your work around). If you have an idea for a research proposal, start writing whatever you can, a little bit at a time - it will save you a lot of work come crunch time. Keep a calendar (or two) to remind you of your appointments; being able to look ahead at a deadline will help you plan out your time better.

And most importantly, remember to take time for your own well-being. It's really, really easy to get overstressed in grad school. Between teaching, research, writing, taking classes, and dealing with everyday life, you're going to be really busy. You may well be putting in longer hours than a regular job, just to get things done - and that's okay. But make sure that you take time off for yourself, because your mental health is just as important as your degree. I feel like I came from a rigorous academic background, and I still had rough patches getting adjusted to grad school; everyone does. But I learned that I had to step away from it and do fun things for myself - hiking, shopping, going out with friends, watching cheesy horror movies, blogging, etc. It's made the whole experience a lot more enjoyable, and I think that even though grad school is difficult, if you're not enjoying it on some level, there's something that needs to change.

February 2010 dome collapse deposits at Soufriere Hills

2010-09-08T09:27:00.001-04:00

If you ever want to visit a post-apocalyptic wasteland, someplace that's been run over by pyroclastic flows would be a great choice. On February 11 of this year, a partial dome collapse on the northeastern flank of the Soufriere Hills lava dome produced spectacular pyroclastic flows, surges, and a 50,000 ft (~15 km) high ash plume. The pyroclastic flows extended the eastern coastline significantly in the area of the old Bramble Airport, and surges were observed flowing out over the ocean on the eastern side of the island.

Here's a photo from the edge of the collapse deposits, below the Jack Boy Hill overlook. In the distance of this photo, you can (just) see a chimney stack. This is one of the only visible structures left in the whole area; even the old Bramble Airport (which would have been visible to the left of the chimney) is now completely buried.

The chimney stack is part of an old sugar mill, and I'm pretty sure that what's visible isn't the whole chimney. To give you a sense of scale, here's yours truly standing next to the stack.

Walking on pyroclastic deposits isn't difficult, but it's not the most pleasant hike I've taken. Ash is nasty stuff, especially when you're kicking it up whenever you walk somewhere. In addition, these deposits are still(!) quite hot; a few inches down is enough to make it uncomfortable to stand in one place too long, and digging less than a foot down, they become hot to the touch.

Here's what the deposits look like in cross-section. Those dark streaks are degassing structures, which are cut off by the most recent deposits on the top of the sections.

As I mentioned before, the Montserrat Volcano Observatory scientists brought us on this hike; in the khaki hat and olive shirt is Dr. Paul Cole, the Director of the Observatory. We're examining one of the boulders that was transported downslope in the collapse - and while it looks pretty big, it's actually one of the smaller boulders that we saw. The largest were the size of small houses! (Definitely not something you want to get hit by, which is why it's a good thing that the people on Montserrat pay attention to the exclusion zones.)

On several of the boulders, we saw examples of marks that are interpreted to have been created by the impact and scraping of one boulder against another during transport. They could be described as slickensides, except here they're glassy surfaces that were created very quickly during an impact, rather than slowly during the scraping of a fault surface. (The study I linked to mentions that in the largest marks, frictional melting formed pseudotachylite, which is basically glass.)

Things like the friction marks above, and this next photo, remind you of just how dangerous pyroclastic flows are. Aside from giant boulders smashing into each other, you also get stronger-than-hurricane-force blasts, poisonous gases and extremely high temperatures. To give you an idea of what that does to the landscape, here's a view of the end of a pumice flow lobe that carried trees with it. All the wood here is carbonized; my best guess is that temperatures of around 400°C (or higher!) were involved. That's about twice as hot as your kitchen oven will go.

Did I mention the force involved in pyroclastic flows? Here's an example: a tree limb thicker than my arm that was snapped in half and then pretty much welded into that position.

Another interesting feature just beyond the pumice lobe were these pit craters, formed when the flow buried a water source, which was then heated to steam and exploded up through the new material.

I think the water in question was probably part of this drainage (this is looking roughly to the west), which we walked down on our way back to the vehicles. While these deposits do retain their heat, there doesn't seem to be enough time to really weld them together, so they're pretty easily washed away by precipitation, and form these sorts of drainage channels.

The channels do make it much easier to see cross-sections, though! There are at least five (probably more) different deposition events represented here, with a lovely pumice-filled channel right in the middle.

I'll try to get to a post on how to distinguish different types of deposits next (and hey, maybe some annotated photos!)

UPDATE: Claire Howard (one awesome reader) sent in some photos of the factory chimney at Trants from May 1995, 6 months before the beginning of the eruption. Turns out that chimney was a lot taller than it is now. Enjoy - and thanks to Claire!

Montserrat and the Soufriere Hills volcano

2010-08-27T11:27:00.000-04:00

This summer I was lucky enough to take an absolutely amazing field trip on the island of Montserrat, where my advisor spent two weeks showing us around her old stomping grounds. And let me tell you, I would have no problem doing volcanology on a Caribbean island for a while...

Montserrat is a beautiful island, but it's small - and the fact that the Soufriere Hills volcano has made a bit more than half of it unlivable hasn't helped any. Here's a basic map of the island, with the approximate boundaries of the exclusion zone (which changes depending on activity):

From http://travel.state.gov/travel/cis_pa_tw/cis/cis_974.html

Montserrat is part of the Lesser Antilles volcanic arc, which is formed by the subduction of the Atlantic tectonic plate below the Caribbean plate. Most of the islands in the arc have andesitic volcanoes, which tend to produce explosive eruptions and lava domes. Montserrat itself is composed of three different volcanic centers: the Silver Hills in the north (the oldest, where the rocks date to ~11-25 million years), the Centre Hills in the center (9.5 - 5.5 million years), and the Soufriere / South Soufriere Hills in the south (at least 1.7 million years to the present). (For more information on the argon-argon dates that produced these ages, see the Harford et al. reference below.)

Maps of the Antilles arc and the volcanic centers on Montserrat. From Smith et al. (2007), Prehistoric Stratigraphy of the Soufriere Hills–South Soufriere Hills Volcanic Complex, Montserrat, West Indies.

The island is very densely vegetated, with most towns clustered around the coast; this also means that the best (old) rock exposures are in sea cliffs. (Hence we spent a lot of mapping time on beaches. Not a bad deal, eh?)

Montserrat from the north, with the Silver Hills in the foreground and the Centre Hills just visible below the clouds.

When seismic activity (namely earthquake swarms) started happening in 1992, the island was still trying to recover from the damage caused by Hurricane Hugo in 1989. In 1995, phreatic explosions (involving heated groundwater, but no lava eruption) began opening vents in English's Crater. Ash from larger explosions prompted the evacuation of southern Montserrat in August of 1995, and by November a lava dome began growing in the crater. Since then there have been a number of periods of dome growth and collapse, during which the volcano has built the original lava dome into a large edifice that completely covers the old crater. Dome growth has been accompanied by pyroclastic flows, lahars, and ash venting; occasional periods of explosive eruptions and phreatic activity have occurred.

The current lava dome viewed from Jack Boy Hill (east side of the island), with a large collapse scar visible to the right. Because this is a tropical island, it's pretty unusual to see the dome this clearly, so we got lucky. (The same thing happens in Central America - my field area is frequently clouded in.)

Looking at the west side of Soufriere Hills. The light gray slope on the left marks a point where pyroclastic flows and dome collapses have filled in old topography, as well as burying the former capital of Plymouth. The bluish cloud hanging over the volcano is a steam and gas plume, which gets its bluish tint from sulfur gases.

Dome collapses at Montserrat are impressive, often accompanied by explosions, and can involve anywhere from tens of thousands to millions of cubic meters of material. The most recent occurred in February of this year; you can see video (thermal and normal) at the Montserrat Volcano Observatory website, and I'll be showing photos of our field trip to the collapse deposits in a later post.

Another Jack Boy Hill view, this time of the February 2010 collapse deposits. This is the site of the old Bramble Airport, and it's been run over by various other pyroclastic flows in the past, but until February the old airport and some structures were still visible. Not anymore!

We had the opportunity to spend some time at the Montserrat Volcano Observatory, where the scientists graciously spend time showing us the ropes (and taking us on some great field trips).

The Montserrat Volcano Observatory perched above the Belham Valley. Swanky!

Examining friction marks on a boulder in the February 2010 deposits.

In return, we gave lunchtime presentations on subjects relevant to andesitic dome eruptions, and helped map some of the older deposits on the west side of the island. In Smith et al. (2007) - mentioned above - the authors mapped cliffs on the east (old airport) side, but presumably got distracted by the new eruption before they could get to the rest of the island. As part of our class requirement (yes, we got credit for this trip!), we did a survey of sea cliffs on the west side of the island, which meant many long and grueling hours spent on beaches and in boats.

As field locations go, you really can't beat one that's steps away from the beach (and the beach bar).

How could anyone work in these conditions?

It was a fantastic trip, with great opportunities for seeing old and new products of explosive volcanism (sometimes side by side). The staff at the MVO were very gracious, as was everyone we met on the island. (Perhaps the only downside of the trip was the state of my legs after two weeks of being munched on by tropical mosquitoes; apparently I'm tastier than the majority of the folks who went on the trip.) More discussion to come of the February 2010 collapse, the older volcanics, and how to distinguish different kinds of deposits!

References

Harford, C.L., Pringle, M.S., Sparks, R.S.J., Young, S.R., 2002, The volcanic evolution of Montserrat using 40Ar/39Ar geochronology. In The Eruption of Soufriere Hills Volcano, Montserrat, from 1995-1999 (T.H. Druitt and B.P. Kokelaar, eds.), p. 93-113.

Smith, A.L., Roobol, M.J., Schellekens, J.H., Mattioli, G.S., 2007, Prehistoric Stratigraphy of the Soufriere Hills-South Soufriere Hills Volcanic Complex, Montserrat, West Indies. The Journal of Geology, v. 115, p.115-127.

In the Humorous Vein #14

2010-08-24T13:48:00.000-04:00

I'm still getting ready for the semester here, so at the suggestion of A Lifelong Scholar, I'm resurrecting an old series I was working on and giving you a humorous interlude. (This is one of the photos from my travels this summer; can anyone guess where it was taken?)

Still not dead yet...

2010-08-20T13:15:00.000-04:00

Sorry for the long absence, folks - there was traveling galore this summer! And naturally there will be photos once I work out why the internet at home isn't functioning.

Role and impacts of the geoblogosphere (July Accretionary Wedge)

2010-07-29T16:52:00.000-04:00

Not that kind of impact! Courtesy NASA/Don Davis.

David Bressan over at History of Geology poses the questions du mois: How can geoblogging impact society and "real geology"? Should and can we promote the "geoblogosphere"? Are blogs private “business” or public affairs? Are institutions undervaluing the possibilities given by this new method of communication?

To avoid a really long post in response to all of the questions - though they're certainly worthy of dicussion! - I'm going to stick to one, and talk about how I see geology blogs impacting society and non-virtual geology.

When I first started this blog, I'm sure I wasn't thinking that I would be reaching a very wide audience - I was mostly aiming for the geology graduate student who was looking for advice and maybe a little commiserating once in a while. The volcanology part seemed logical, since that's what I wanted to study, and the blog itself was a good way to hone my writing skills. But after a little while poking around the existing geology blogs, I became aware that we were reaching a wider audience, and not just a scientific one. People who may not even have taken a geology class were finding the geoblogosphere and starting to interact with the bloggers - commenting, asking questions, looking for information. Looking for education.

The geoblogosphere is a fantastic way for a person who doesn't have access to continuing education, or who never had an opportunity to take a geology class in high school or college, to learn a little bit about the Earth. Not only do they get to read what we as geologists find interesting, but they can ask us to talk about what they find interesting - through emails, comments, requests for posts, etc. It's a step toward breaking down the idea that scientists are somehow elitist and removed from society. I don't want people to think of us like that; we're not from another planet, after all, even if we sometimes study them.

I don't think geoblogging is only breaking down barriers between Earth and space scientists and the non-scientist public, either. Personally, I've found that geoblogging has opened up a whole new social and professional group to me - one that I never would have been able to build from the "traditional" routine of academic collaboration and conferences. I hope that someday I'll be able to collaborate with my fellow geobloggers and broaden the impact and usefulness of my work. And I think that's a worthy goal for E&S scientists as a whole: not to only bury themselves in a narrow area of research, but to remember that acquiring new knowledge depends on a foundation drawn from many disciplines.

In the past, collaboration depended on the post office, the telephone, and face-to-face meetings; the final products of our research on conference schedules and journal editors. With email and blogging, we now have an even faster and more powerful way to share our work with each other and the public. Though it certainly will not - and should never - replace the systems that have developed over centuries of research, I think geoblogging is a wonderful way to supplement them.

Fundraising update: $10 for Guatemala

2010-07-27T09:58:00.000-04:00

Geologizing is still on hold for a bit (it's amazing how hard it is to get your brain back into 'work' mode after field work happens), but here's an update on the fundraising drive for the Santiaguito Volcano Observatory in Guatemala. Donations have started to come in, but this is the official kickoff, and guess what? The International Volcano Monitoring Fund has made it incredibly easy (and affordable!) to help support volcano monitoring in Guatemala. Want to know more? Here's a message (and a flier) from IVM-Fund President Dr. Jeff Witter:

(Click on the flier for a bigger version!)

"Today we launch the first official fundraiser for the International Volcano Monitoring Fund. Please take a minute to read the attached flyer, which highlights the great volcano monitoring support program we have recently established in Guatemala. Please consider making the requested $10 donation. With your help, along with the support of the geology and scientific communities at large, we are hoping to raise $10,000 for Guatemala volcano monitoring. With this money, the IVM-Fund will help outfit the Santiaguito Volcano Observatory with volcano monitoring equipment so that Guatemalan scientists can keep watch on one of Guatemala's most active and dangerous volcanoes. The IVM-Fund Guatemala program intends to make a meaningful impact, improving safety at Guatemalan communities near Santiaguito volcano.

"A sincere thank you in advance for your support and for the continued support of those of you who have already donated.

"Please contact me (Dr. Witter) directly or check out the specific project webpage for more detailed information on how we're supporting Guatemala: http://www.ivm-fund.org/guatemala/. To make a donation, please click on the DONATE NOW button at: http://www.ivm-fund.org/donate/."

Ten dollars for volcano monitoring is something that even a grad student can afford, and I hope that everyone who reads this will consider helping with a donation!

Blogging break again

2010-07-06T14:35:00.000-04:00

I'll be busy volcanologizing for the next two weeks, so the blog's on break again. Hope you're enjoying your summers!

Bandelier National Monument

2010-07-05T16:08:00.002-04:00

One of the neat things about Los Alamos is that Bandelier National Monument is only a few minutes away. The volcanic tuff at Bandelier erupted from the Valles caldera about 1.25 million years ago, but it's not just a site of geologic interest; it's also an archaeological site. Bandelier refers to Adolph Francis Alphonse Bandelier, a Swiss-American archaeologist who conducted research into the history of the Pueblo people in the American southwest.

On the drive to the park visitor center, there's some fantastic columnar jointing in the tuff. (Columnar jointing occurs when hot volcanic material, either a lava flow or pyroclastic deposit, cools from the outside in and shrinks, forming cracks. These cracks often create geometric shapes that extend down into a deposit, creating columns.)

In the Frijoles Canyon, there are scads of cliff dwellings and the ruins of villages of the Ancestral Pueblo people, who moved into the region around 10,000 years ago. (They were formerly called "Anasazi" by archaeologists, but today's Pueblo people consider the Navajo term disrespectful). The village below was most highly developed in the late 1400s, and contained multistory dwellings and storage buildings.

The cliff dwellings at Bandelier are located mostly on the south side of the canyon, which means that they stay cool in the summer and warmer in the winter. It was a very hot day when I visited, and there was a significant temperature drop once you were sheltered by the cliffs.

Many of the cliff dwellings used to have structures built in front of them, leaving the caves as back rooms. Holes for the ceiling poles are still visible in the tuff, which is relatively soft and quite easy to hollow out.

One of the most interesting sites in this area of the park is known as the Alcove House, a huge shallow cave in the canyon wall. It holds a reconstructed kiva and the remnants of dwellings, but it's quite a challenge to reach - and not at all fun for anyone who's afraid of heights! Like many of the other cliff dwellings in the park, the Alcove House is only accessibly by ladder; unlike the dwellings in the earlier photos, the ladders are very long (140 feet altogether). The photo below shows one of three that you have to climb to get up there!

It's a little hard to take photos of the whole alcove when you're in it, but the view down Frijoles Canyon is excellent. It also highlights how the natural propensity of the Bandelier tuff to erode into caves - something that the first visitors to the canyon certainly noticed and took advantage of!

I only had one day to explore Bandelier, which is unfortunate (it has more than 70 miles of trails), but I'm glad I had the chance to visit on this trip. This area offers a fascinating blend of volcanology and archaeology, something that I (with my sadly unused archaeology minor) really appreciate.

Los Alamos & environs

2010-06-25T12:13:00.000-04:00

While I was visiting Los Alamos recently, I made sure I got out of the lab to do a little hiking. Here are the photographic results:

This hike was on the Quemazon trail, which starts in the western part of the town of Los Alamos. (There are a number of trails that can be accessed from the neighborhoods around the lab - even a few you can hike to get to work in the morning!) The trail makes several loops up a mesa, depending on how far you go, and gives you some great views of the area.

The trail itself is, in many places, worn down into the relatively soft Tshirege member of the Bandelier tuff. The volcanic tuff was erupted about 1.25 million years ago in the collapse of the Valles Caldera, and underlies much of the town. (The path on the left is used for foot and bike traffic, although it looks like something mechanical came in and roughed up the tuff on the right side.)

A vesicular example of the tuff:

And a close-up of a hand sample. This stuff is chock-full of feldspar, and the sandy parts of the path sparkled pretty dramatically in the sun.

A "hand sample" of sand from the path. There's almost more feldspar than matrix in this, though it could be because the feldspars were just collecting in the area that I happened to scoop it up from. (Some of these feldspars were iridescent, which sometimes happens with sanidine feldspar; it's probably a safe bet that they are sanidine, which is a very common mineral in explosive volcanic rock.)

The hills above Los Alamos are unusually bare for this type of high desert, and that's because they're still recovering from the May 2000 Cerro Grande fire. The fire, which was started as a controlled burn, destroyed 48,000 acres of forest, more than 400 homes and part of the Laboratory in Los Alamos. (The houses that were burned in the fire were scattered all throughout the neighborhoods in town, and there were quite a few instances where one house was destroyed but another just across the street was untouched. Even now, there's quite a bit of rebuilding still going on.)

One (minor) advantage of the fire is that it made the views of the Lab a little clearer; I can imagine that ten years ago, this shot would have been mainly taken up by pine trees, like the dark green ones further downslope. This is only a small part of the Laboratory - there are more sites elsewhere in town - but it's the main area of office buildings and includes a research library.

Thinking about the Cerro Grande fire made me a little nervous while I was out there, because there were a number of smaller fires burning in the Jemez Mountains to the north; fortunately, they were about 15 miles away, and not likely to threaten the town. Still, it was a bit unnerving to walk home every afternoon and see this:

I am also, it seems, allergic to the combination of burning pine trees and pine tree pollen, so it was a bad week for my sinuses.

The Santiaguito Volcano Observatory needs your help!

2010-06-19T19:12:00.000-04:00

While I was in Guatemala working at the Santiaguito lava dome complex, my field group had a lot of help from the Instituto Nacional de Sismologia, Vulcanologia, Metereologia e Hidrologia (INSIVUMEH). And when I say a lot, I mean "helped organize every logistical detail of the trip and gave us a place to stay at the Santiaguito Volcano Observatory". I could never have done any of this work without their help, and now I'm going to try and help them out in return.

The Santiaguito Volcano Observatory needs our help.

Unlike the geological organizations in the U.S. and Europe, INSIVUMEH doesn't have a lot of money to throw around. The scientists and observers at Santiaguito (and at other volcanoes in Guatemala) don't have the equipment they need to easily and accurately monitor active volcanoes. It's not a matter of needing big pieces of high-tech instrumentation; the folks at the Observatory don't even have the basics that we all take for granted - such as digital cameras, radios, and GPSs. What's more, even though they have a seismic station collecting data about the Santiagutio domes, there's no way to receive or process the information at the Observatory, because they don't have the computers to do it.

In light of the recent large eruptions at Santiaguito and Pacaya, this is dismaying. The people who live and work around Santiaguito depend on the Observatory to help keep them safe, and INSIVUMEH's scientists don't have the basic tools they need to do their work. I've talked about the hazards of living near an active volcano in the past, and the key to doing it safely is to have diligent, well-equipped scientists monitoring volcanic activity. The INSIVUMEH volcanologists and observers are incredibly dedicated to their work, but there's a point when equipment needs simply hamper their ability to be effective. Because the average person in Guatemala lives on US$2 or less a day, there's no way they can afford to spend their own money to supplement their equipment. But we can, and that's why I'm making this announcement - and asking for your help.

Donate to the International Volcano Monitoring Fund!

The International Volcano Monitoring Fund (IVMF), which was created by Dr. Jeff Witter, has been set up specifically to help volcano observatories in developing countries. Dr. Witter has agreed to extend their current endeavors to purchasing equipment for the Santiaguito Observatory, and has just launched a new webpage where you can find out how to help: http://www.ivm-fund.org/guatemala/. He and I have been working with Gustavo Chigna, the director of INSIVUMEH's volcanology programs, and Rudiger Escobar, a Guatemalan PhD student in volcanology at Michigan Technological University, to develop a list of what the Santiaguito Volcano Observatory needs.

The equipment they've requested runs all the way from smaller items like tape measures and rock hammers to more expensive things like desktop computers (to receive and process seismic signals) and laser rangefinders. Each item comes with a dollar amount needed to purchase it and a description of how it will be used. You don't even have to purchase the whole item - like the DonorsChoose campaign that the geobloggers participate in every year, every little bit helps. The IVM Fund is a non-profit organization, so you can be assured that as much of your donation as possible will be going toward funding Guatemalan volcanologists.

Please, help my colleagues in Guatemala do their work! I'm incredibly lucky that I don't have to worry about being able to afford my equipment, and I want to make it possible for the volcanologists at INSIVUMEH to do their work without the same problems. Because any fundraising effort is a long-term endeavor, I'm going to place a permanent link on the blog and periodically update you all as the IVM Fund collects enough to start purchasing equipment. (I also think that t-shirts may be in the works for the future - you'll be able to donate toward volcano monitoring efforts and add to your geologic wardrobe!)

Eruptions - especially the ones that we've seen this year - remind us all that it's necessary for volcanologists to keep a close eye on active volcanoes. Like any scientist, they need the proper tools to do that. When they have them, volcanologists can do a lot to help safeguard peoples' lives, livelihoods and homes. If you think you can spare a little money, please help the volcanologists at the Santiaguito Volcano Observatory do just that!

Volcano Vocab #5: Caldera

2010-06-18T20:06:00.001-04:00

Part of my research this summer involves visiting Los Alamos to learn how to work with a computer model; in addition to one of the world's greatest research laboratories, northern New Mexico also hosts the Valles caldera, a major volcanic center north of Albuquerque. (Pretty much everything around me is volcanic, which means that whenever I drive or bike anywhere, I'm always staring at the scenery and going "holy crap, that's amazing!")

Caldera ("cal-dare-uh") is a Spanish word meaning "cauldron", and it describes a type of large, bowl-shaped volcanic structure. Calderas are created by collapse of the roof of a magma chamber after the chamber's contents have been removed, either in effusive or explosive eruptions. They're technically not craters, which are smaller and usually located on the summit of a volcano, but much larger features that form when a volcano expels the contents of a big magma reservoir and then collapses. (If activity continues after this happens, it can even create new stratovolcanoes within the caldera.)

The eruptions that form calderas are big - hundreds to thousands of cubic kilometers of material is involved. Collapse features that form over magma chambers that large are often not recognized as volcanic features until they're seen from the air, because they're simply too large to distinguish from the ground. On the volcanic explosivity index (VEI), caldera-forming eruptions top the chart - and in the case of some, are too big to even show on the chart:

VEI figure from the USGS Volcano Hazards Program Photo Glossary.

To give you an idea of what this translates to in reality, here's part of the Valle Grande in the Valles caldera:

This meadow is only a fraction of the whole caldera, and you can't even see the far walls because they're hidden behind the resurgent and smaller domes. Here's a map of the whole caldera:

View Larger Map

The Valle Grande is the light green patch in the southeast; the hills in the background of the photo are the Redondo Peak resurgent dome and smaller lava domes, which are pretty common post-caldera-eruption features. Resurgent domes are thought to be related to rebounding of the caldera floor, possibly due to new magma intrusion; the lava domes represent later eruptions through fractures. (If you want to know more about the specific geologic history of the Valles Caldera, Garry Hayes over at Geotripper has a great post from last year.) Some well-known examples of calderas in the United States are Yellowstone in Wyoming, Crater Lake in Oregon, Long Valley in California, but there are plenty of others: Krakatau and Tambora in Indonesia, Santorini in Greece, and Colli Albani and Campi Flegrei in Italy, to name a few.

I'll leave you with a photo from the rim of the Colli Albani caldera in Italy, with the Faete stratovolcano to the left of center:

Guest Post at "The Plainspoken Scientist"

2010-06-15T18:30:00.001-04:00

All right, so I'm still caught up in summer research (and have managed to catch some sort of cold, which is ridiculous at this time of year). Until I get back to more regular posting, I offer for your reading pleasure a guest post on the American Geophysical Union's blog The Plainspoken Scientist:

"Why I Blog: Jessica Ball (Magma Cum Laude)"

The AGU blog just started up in March, and they already have some excellent guest posts up (including one by Callan over at Mountain Beltway, who started blogging around the same time I did).

I have some excellent photos to go along with my next installment of Volcano Vocab (which is sadly no longer a regular feature, but I'm going to work hard to get back to it). Look for the post before the week is over!

Volcanoes everywhere...Is there a link? (EARTH Magazine article)

2010-06-05T15:03:00.000-04:00

Like Brian over at Clastic Detritus and Callan of Mountain Beltway, I've also recently contributed an article to EARTH Magazine's website. Mine talks about the recent eruptions at Pacaya and Tungurahua, with a little bit of exposition on the inevitable question of whether they're linked. (Nope!)

I'm digging into some research in the next few weeks, so posting will be a little sparse (again). I'll try to get the Volcano Vocab feature started up again, though - I've been sadly neglecting it.

Perception of volcanic hazards in Iceland

2010-06-03T14:42:00.000-04:00

The eruption may be subsiding a bit, but there is still a lot of discussion (and arguing) centered around the Eyafyallajökull event. It's not entirely surprising; most people in Europe don't have to deal with active volcanoes, and the last time an Icelandic one caused widespread trouble was in the 18th century. But what about the Icelandic response? One might assume, given the prevalence of volcanic and geothermal activity in Iceland, not to mention hazards caused by volcano-water interaction, that Icelanders might be better prepared than other Europeans to deal with natural hazards. But is that really the case?

In "Resident perception of volcanic hazards and evacuation procedures", published in 2009 in Natural Hazards and Earth Systems Science, Australian and Icelandic scientists set out to evaluate how Icelanders perceived risk and what their response would be to an evacuation drill for a jökulhlaup hazard. The study was conducted in March 2006 in the jökulhlaup hazard zone of Rangávallasýsla, a region immediately adjacent to the Mýrdalsjökull and Eyafyallajökull glaciers and the Katla volcano, which is notorious for producing jökulhlaups.

Figure 1 from Bird et al. (2009). The jökulhlaup hazard zone of Rangávallasýsla. The hazard zone is the maximum area that a catastrophic jökulhlaup is expected to flood. Evacuation centers are represented by blue triangles.

The authors of the study used a combination of methods to assess the reactions of residents and emergency officials: they directly observed an evacuation drill, did face-to-face interviews with officials and residents, and distributed surveys to those involved in the drill. The authors also discuss the parameters of the drill:

If an eruption is imminent residents would be notified via a text message to their mobile phone. If residents do not have a registered mobile phone number a recorded message would call through to their landline. Upon receiving this message residents have 30 minutes to prepare to evacuate. However, if an eruption occurs without precursory activity, residents will be instructed to evacuate immediately. Before leaving, they are required to hang the evacuation sign outside their house to indicate that they have left. Certain residents in each region have volunteered to ‘sweep’ their local area to ensure their neighbours have left for the evacuation centres...
To test the proposed evacuation plan the ICP conducted a full scale evacuation exercise on 26 March 2006 in Rangávallasýsla. Approximately 1200 residents live within the hazard zone (K. Þorkelsson, personal communication, 2006) and for the purpose of fully testing the evacuation plan residents were not informed of the timing of the eruption scenario. Instead residents were instructed to go about their business as usual until they received an evacuation message (R. Ólafsson, personal communication, 2006). The mock eruption began at 10:55 local time (LT) and the first evacuation message was communicated to residents at 10:59 LT. Residents then had 30 minutes to complete the instructions on the hazard sign (Fig. 2) before evacuating their homes to their designated centre.

So what were the results of the evacuation drill and the study?

Many residents did not receive notice of the evacuation, but about 65% of the local population still registered at evacuation centers. Some of the reasons cited by the remaining 35% for their non-participation included lack of communication from officials, reluctance to leave their livestock, or that they were simply not interested in the drill. The response from those who did participate, however, was overwhelmingly in favor of the drill.
71% of evacuation participants were able to correctly describe the evacuation procedures they were supposed to follow during the drill, and 94% were able to define what a jökulhlaup was (and knew that it was the major hazard associated with an eruption of Katla).
Many of the residents of towns on higher ground stated that they would remain in their homes rather than evacuate, citing that it was safer there than on roads and that they thought the flood stage of the glacial drainage would be too low to reach them.
Many of those surveyed - especially farmers - did not think that 30 minutes was enough time to prepare for an evacuation, since they had livestock to care for in addition to dealing with their homes and families.
"None of the participants from the 18–30 year age group and very few from the 31–50 year age group could correctly describe a brief volcanic history of Katla." Some residents who had family members who had seen the 1918 Katla eruption had knowledge of what Katla was capable of, but this has apparently not been passed down to their children.

This paints an interesting picture. Most of the residents, even if they didn't participate in the drill or completely understand the potential hazards associated with an eruption of Katla, were still very well informed about what they should do in an emergency. Many evacuated even though they didn't receive a direct message from emergency officials (mostly because of community volunteers who helped spread the word of the drill). But it is troubling that a large number of people living near Katla (and Eyafyallajökull) knew very little about the past activity of the volcanoes. This is often the case when volcanic disasters have passed partially or completely out of living memory, but given that volcanic activity is extremely common in Iceland, it's not particularly reassuring. The authors suggest that a lack of outreach by public officials may be the cause for this:

Our participants are aware of jökulhlaup, tephra, lightning and rock fall hazards but they have not been provided with enough information to enable them to make an informed decision on whether to evacuate or take shelter in place and how to best protect their livestock.

Finally, the authors comment on some of the underlying problems with the evacuation itself, most having to do with communication issues (again):

Results from our study highlighted problems associated with communication during the evacuation exercise and the possible need to find alternative modes which do not rely so heavily on technology. In light of this, scientists and emergency management officials should collaborate with media agencies and the public in order to promote the use of media resources and, to ensure hazard information is accurately distributed in an understandable form. Furthermore, the importance of the sweepers’ role during an evacuation should be emphasised as they may provide the only communication link between emergency management and farming communities. Recent public meetings which involved residents in risk mitigation efforts are a positive step toward empowering residents with evacuation procedures and preparedness strategies.

What's the bottom line? It's an interesting one: people near this volcanic center in Iceland seemed to be fairly well informed about what they should do in an evacuation. But they weren't necessarily as knowledgeable about the hazards that necessitate the evacuations, even though they live very close to an active (and now erupting) volcanic center. (Given the recent eruptions, I suspect that a follow-up study would show a distinct change in this observation. If anyone comes up with one, I'd be interested to see it.) This study does emphasize again the importance of good communication between scientists, emergency officials and the public; in an emergency, if people are better informed about hazards and what they should do to avoid them, evacuations will run more smoothly and officials will waste less time dealing with confusion and misinformation.

Bird, D., Gisladottir, G., & Dominey-Howes, D. (2009). Resident perception of volcanic hazards and evacuation procedures Natural Hazards and Earth System Science, 9 (1), 251-266 DOI: 10.5194/nhess-9-251-2009

Posting again soon...

2010-05-25T20:58:00.002-04:00

Got caught up in various projects, but I'll be settled down again in a few days (and hopefully back to posting).

Reflecting on risk

2010-05-18T15:33:00.000-04:00

USGS photo of the May 18, 1980 eruption.

I don't have any stories to share with you about the 1980 Mount St. Helens eruption, since I wasn't around then - and the other geobloggers are doing a fine job of collecting reminiscences already.

Volcanologists, like everyone else, sometimes joke about their jobs, but it's anniversaries like today that have prompted me to reflect on it instead. I love the work that I'm doing, and what I'm training to do. It's exciting, and takes me to exotic places, and I get to learn all sorts of fascinating things about how volcanoes work. But whenever I'm near or on an active volcano, there is always an element of danger as well. Because volcanoes are natural systems, they always have some element of unpredictability. It is possible for scientists to forecast what a volcano may or may not do, but it's impossible to predict anything with absolute certainty, so we can't be absolutely sure that any part of a volcano is safe, no longer how long it's been dormant or how mild its activity seems. Not to mention that volcanic settings in general are not safe or nice - there are any number of dangers from unstable or rough terrain, toxic gases, and just the remoteness and inaccessibility of many volcanic areas.

Those are all things I have to consider when I'm doing fieldwork at active volcanoes. In the past year, I've visited Stromboli and Etna and Santiaguito; this summer I'll be traveling to Montserrat, where Soufriere Hills is still erupting. Each time I set foot on a volcano, I acknowledge - consciously or not - that the chance to learn about it overrides the potential hazards of the setting. I don't take unnecessary risks, or make careless or foolhardy decisions if I can avoid it; I'm not going to wander into an exclusion zone or into an active crater just for the sake of samples and photos. But the recent significant eruption at Santiaguito reminded me that even the settings that seem safe at one moment can become deadly in the next, and the lateral blast that occurred at Mount St. Helens thirty years ago today is an excellent example of the same.

USGS photo of David Johnston from April 4, 1980.

Dr. David Johnston was one of the 57 people who lost their lives in the 1980 eruption of Mount St. Helens. He knew the dangers of working on an active volcano, and no one could possibly fault him for being at the Coldwater II observation station when St. Helens erupted; if it hadn't been him there, it would have been someone else. The volcanologists working there at the time hadn't even considered that the volcano might produce a lateral blast, though they - including Dr. Johnston - were certainly uneasy about the setting. In interviews, his friends, family and colleagues invariably say that Dr. Johnston died doing something that he loved. As a volcanologist, I am doing something that I love whenever I go to study an active volcano; I can't imagine myself as happy in any other job. But it isn't a safe job. I know it's difficult for my family to think about, and I don't like to bring it up, but there is always a chance that I could be hurt - or worse - working at an active volcano. It's the same risk that many of my friends and professors take. True, all of us take risks every day - driving, flying, playing sports - but volcanology involves unique risks that most people don't have to deal with on a regular basis.

I hate to write such a depressing post about what would otherwise have been an exciting event, but it's what's been on my mind today. Volcanology is an exciting, unique science; volcanic eruptions are fascinating events. But it's always good to remember that this is one of the sciences where the researchers take risks for the sake of their work.

Geo-image Accretionary Wedge

2010-05-17T11:29:00.001-04:00

My geo-photo of choice is a bit of interplay between the forces of geology and biology: an ohi'a shoot growing from a crack of a lava flow on the flank of Mauna Ulu, on the Big Island of Hawaii. The photo is significant to me for a number of reasons: This was my second trip to Hawaii, but the first time I'd had a chance to learn the techniques of volcano monitoring; it was also the first time that I'd really begun to understand the workings of an active volcano. This hike, part of a volcanology field course run by UH Hilo, took us up a lava channel to the summit of Mauna Ulu, through more forms of basaltic lava than I'd ever imagined existed. It was fascinating stuff. It was also a surprise to come across little enclaves of plants every so often - the first colonizers of a totally inhospitable environment. The contrast of the green leaves of the ohi'a and ferns against the dark lava flows was striking, and quite beautiful.

This photo reminds me that even the destruction caused by volcanoes doesn't last forever. Tomorrow's anniversary - that of the May 18, 1980 eruption of Mt. St. Helens - brings to mind the amazing transformation that the blast zone has undergone in the 30 years since the event. The same persistent forces were at work on Mauna Ulu since its eruption ended in 1974, and the patches of life that I saw in a lifeless terrain were a subtle reminder of the processes of change.

Volcano Vocab #4: Lahar

2010-05-07T10:25:00.000-04:00

As suggested by a commenter on the last Volcano Vocab post, here's a water-and-volcano-related term for you: Lahar ("lah-haar").

Lahar is an Indonesian word for a mudflow of volcanic material - that is, a mass movement of volcanic debris that contains some amount of water. (A dry flow of volcanic material would usually just be called a debris flow or debris avalanche.) The key thing that distinguishes a lahar from a "regular" mudflow is the presence of volcanic material in the flow, which can include tephra, ash, hydrothermal alteration products, blocks of lava flows, and other pyroclastic materials. Some descriptions liken this mixture to a flow of cement, and it's capable of moving house-sized boulders huge distances from their source.

Lahar deposits characteristically show poor sorting (lots of different sizes of material, from boulders to sand), multiple rock types, rounded clasts, and muddy matrix supporting the clasts. (Sometimes in deposit matrices you can find rounded voids where bubbles of air were trapped as the deposit hardened around them!) Lahars are most common on stratovolcanoes, but (as we've seen in Iceland), other types of volcanoes can also create the correct conditions to form a lahar. Lahar formation depends on having lots of loose material, and the addition of lots of water over a short period of time (such as from a melting glacier, a hurricane or storm, or a breached crater lake, among other things). They do not require the volcano to be actively erupting, which is one reason why they are so dangerous.

Here's a video of a lahar from Mount Ruapehu in New Zealand (March 2007):

Lahars are an especially dangerous volcanic hazard because they appear and disappear so quickly. Lahar debris that's deposited in a riverbed can easily be eroded by normal river flow, and lahars that have spread beyond valleys and drainages can easily become reclaimed by vegetation. In fact, one of the most devastating lahars to have come from Mount Rainier in Washington State (the Osceola Mudflow) is now covered with small towns. Because the people in the area are now aware of the danger a repeat lahar would present, they are required to hold evacuation drills. Lahars are somewhat easier to monitor and avoid; acoustic flow monitors (specially calibrated seismometers) can be placed in source zones, and a timely warning can be sent downstream when lahar signals are detected. Sometimes evacuation can be simply a matter of climbing to a higher elevation, although on a floodplain it could be necessary to travel much greater distances to safety, but it does require advance warning.

Armero, Colombia, destroyed by lahar on November 13, 1985. Photo from the USGS CVO website.

Lahar warnings aren't always heeded, however. It's impossible to mention lahars without also mentioning the town of Armero in Columbia. On November 13, 1985, a small eruption of the nearby volcano Nevado del Ruiz melted part of the snow and ice capping the volcano's summit, and produced a lahar. Volcanologists knew that river valleys on the volcano's flanks could channel lahars toward populated areas, and sent warning to towns in the lahar's path; unfortunately, local officials either received incomplete or conflicting information, and/or decided not to listen to the scientists' warnings. As a result, more than 23,000 people were killed in Armero and nearby villagees, when they could have reached safety by climbing only a short distance up the slopes on the sides of their valley. This tragedy drove a USGS scientist to develop the Acoustic Flow Monitors mentioned above, in hopes that more deaths could be avoided; the system is now used at lahar-prone volcanoes worldwide.

Where on (Google) Earth #201 - hosted for JimmyJames

2010-05-04T09:21:00.001-04:00

Having not posted anything for a while, I was trying to think up something non-taxing to write about (don't want to take on too much on my birthday!) Fortunately, JimmyJames, the last winner of Wo(G)E, made it easy for me - he's ready to reveal the next edition of Where on (Google) Earth! So here it is:

"This is my first win of Where on Google Earth and I'm honoured to be amongst the folks that participate in this contest. I should admit right away that I am not a geologist (nor indeed a blogger) but I have tried to make the WoGE #201 a challenging puzzle.

This edition of WoGE#201 reveals yet another attractive example of folded sedimentary strata.

As ever, to win WoGE find the Longitude and Latitude of the image, identify the country / area and describe the geological significance of the feature, then post this information in the Comments section below. The first one to post the correct information will go on to host the next edition of WoGE.

With respect, I'm invoking the (Ron) Shott rule: "Previous winners must wait at least one hour for each win that they have before posting a solution - other comments would be okay".

Good luck to all of you! And a heartfelt thanks to 'Tuff Cookie' for hosting my post!

To compensate for the low res Google imagery, I have supplemented it with some higher resolution aerial orthophotos for your viewing pleasure."

(Click to see the enlarged versions!)

Large Santiaguito eruption yesterday morning

2010-04-27T10:17:00.001-04:00

As has already been reported on the excellent Volcanism Blog, Santiaguito experienced a large eruption yesterday morning. Here's a translated announcement that made its way to me from Gustavo Chigna of the Instituto Nacional de Sismología, Vulcanología, Meteorología e Hidrología (INSIVUMEH):

This morning at 06:50 to 09:45 Santiaguito entered a volcanic eruption with 4 face of crater collapses and pyroclastic flows generated within the gullies on the southern flank. The ash column reached heights of 27,000 feet in a westerly direction, northwest and north, forcing the closure of village schools southwest of Santiaguito and in the Quetzaltenango area. A similar eruption to this has not been seen since 1989. The ash is still scattered at 24,000 feet and civil aeronautics alerted air traffic to avoid the plume within a radius of 80 km.

If you haven't seen my earlier posts on Santiaguito (my study area), here's a little background: The Santiaguito lava dome complex is a set of four lava domes at the base of the now inactive Santa Maria Volcano. Currently only one of the domes (El Caliente) is active, and this is the site of yesterday's eruption. Typically, activity on Caliente is limited to 1-3 km high ash-and-gas explosions every hour or two, accompanied by the extrusion of a blocky lava flow from Caliente's summit, occasional pyroclastic flows, and almost continuous rockfalls. Yesterday's event appears to have been quite a bit larger than the usual activity, and has disrupted life for the people living near the domes.

The last eruption at Caliente of this magnitude occurred in 1989, and produced similar ashfall and pyroclastic flows in the drainages on the south side of the domes. Before that, there was the 1973 event, a large collapse and pyroclastic flow from the Brujo lava dome (the last dome to the west of Caliente). Brujo is no longer erupting today, although there is some fumarolic (mostly water vapor) activity. (For more information on the 1973 event, have a look at this paper: Rose, W.I., 1973, Nuée ardente from Santiaguito volcano, April 1973: Bulletin of Volcanology, v. 37, p. 365-371.)

Dealing with ashfall isn't very fun, as folks in Europe can attest, since it gets into everything and makes breathing uncomfortable, if not difficult. On my last field excursion to Guatemala, we were lucky to be out of the way of the ash plume from Caliente - the prevailing winds kept it blowing in the opposite direction of our camp. I'm also quite glad that this event occurred after we were off the domes, because it might have meant dealing with major ashfall at the least, and possibly pyroclastic flows from the column collapse.

Here's some reporting from a few other news sources (this also repeats what was posted on the Volcanism Blog, but I wanted to note the articles that had photos):

El volcán Santiaguito hace declarar alerta naranja - El Periodico (in Spanish, with eruption photo)
Elevan a naranja la alerta en Guatemala por el volcán Santiaguito - EcoDiario (also in Spanish; it appears to have a photo of a large eruption, but I'm not sure if it's Santiaguito or just a stock photo)
Alerta Naranja por ceniza de volcán - El Quetzalteco (in Spanish, with a photo of the reduced visibility on the road leading to the north side of Santa Maria)
Declaran en Guatemala la alerta naranja por la erupción del volcán Santiaguito - Que Es (in Spanish, with a photo that appears to be of Pacaya rather than the domes at Santiaguito)
"Santiaguito Volcano showers sand and ash over Guatemala" - The Australian (via the Agence France-Presse)

My previous posts on Santiaguito and Santa Maria:
Santiagutio Volcano Observatory
Looking backward: Past eruptions at Volcán Santa Maria
Santiaguito lava dome complex
Lava domes, coffee, and a little bit of shaking

Accretionary Wedge #24: My geologic hero

2010-04-23T11:15:00.001-04:00

In considering who I would write about as my geologic hero, I of course had to consider my undergraduate advisor, who I've written about before. (You all know him from this blog, if you've been keeping up with the adventures of William & Mary's Geology Department.) But that would essentially be a rehash of something I've already talked about. Although Chuck was (and still is) an immense influence on my growth as a geologist and a writer, I think that having almost two years of grad school under my belt means I can examine influences a little farther afield.

But who do I look up to as a volcanologist? I'm relatively new to the volcanological scene, and I haven't had the chance to interact with many of the leading lights yet (although quite a few of them are right here at UB). If I were to consider someone who's had an incredible influence on my entire field of study, however, I would tend to look further into the past...and I've come up with one volcanologist who fits the bill.

My pick? Thomas A. Jaggar (1871–1953), an MIT professor who was the founder and first director of the Hawaii Volcano Observatory (HVO). While not the first of its kind in the world (that distinction goes to the one at Vesuvius, which has been around since 1847), the HVO certainly kick-started volcano monitoring in the US. Here's a bit from the HVO History page about his motivation:

"Jaggar saw the need for full-time, on-site study of volcanoes. He had long deplored that to date, especially in America, it was only after news of an eruption was received that geologists rushed from academic centers to study volcanism. There was generally no trained observer there beforehand, and scientists from afar often arrived after the eruption was over. There was then only one volcano observatory in the world, that at Vesuvius established in 1847. Jaggar thought America needed one."

On-site observation of volcanic processes is the key to deciphering the history of a volcano, and gives us the tools to make inferences about the past of volcanoes that have never been observed in eruption. Dr. Jaggar, as he made visits to Martinique following the 1902 of Mount Pelee, and followed them with expeditions to the sites of earthquakes and eruptions in Italy, the Aleutians, Central America, and Japan, became increasingly convinced that such trips were a too-short, inadequate way of observing Earth processes. In 1910, with the support with Lorrin Andrews Thurston, a Honolulu lawyer and businessman; this collaboration led to the formation of the Hawaii Volcano Research Association and, with the financial help of Jaggar's home institution of MIT, the establishment of the Hawaii Volcano Observatory in 1912.

Dr. Jaggar (second from left) preparing to measure the temperature of the Halema`uma`u lava lake in 1917, with stylish hat. My field hats are not even close to that stylish, nor have I ever attempted to do field work in a tie. From the HVO website.

Jaggar went on to work at the Observatory for almost 30 years, during which HVO researchers released more than 1,200 press reports and bulletins about volcanic activity; published The Volcano Letter, a weekly and then monthly report that lasted from 1925-1955; and published copiously in other periodicals outside the Observatory. Jaggar designed and implemented the Whitney Laboratory of Seismology beneath the Observatory (the first site of continuous seismic monitoring in Hawaii), conducted experiments in the Kilauea caldera to monitor subsurface temperatures, and helped pioneer the use of tiltmeters to record the deformation on an active volcano (among other things). The research that's been conducted since at the HVO has been invaluable for the field of volcanology, of course, and the HVO has been a model for other observatories around the world. But why do I think Jagger is a good hero for me? Because he hit on one of the reasons that I wanted to study volcanology in the first place:

"The main object of the work should be humanitarian...prediction and methods of protecting life and property on the basis of sound scientific achievement."

That's the reason I want to study volcanoes - not just for the sake of gaining knowledge, although that's an admirable goal as well. I want my work to be useful to more than just other scientists. It's been fairly obvious recently that most of the world has no idea how to live with the reality of volcanoes in their midst, even when the science of volcanology is firmly in place to study them. There needs to be a working link between science and society, and volcanology - a science which deals with one of the most visible and devastating geologic phenomena out there - should be a major part of that. In my opinion, Dr. Jaggar hit that one spot-on.

Like many heroes, Thomas Jaggar isn't perfect; in order to stretch his limited funding during the building of the Observatory, he allowed convict labor on the site, something that no one would consider nowadays. (The prison camp that supplied the labor was located at the current site of the Kilauea Military Camp in Hawaii Volcanoes National Park). His supporter Lorrin Thurston helped lead the overthrew of Queen Liliuokalani the native monarchy of Hawaii in 1893. Both of them participated in somewhat unsafe experiments (although I will admit that if I had the opportunity to chuck logs into an active lava lake, I probably wouldn't pass it up either).

But it also seemed that he had a good sense of humor - a plus for anyone who works on volcanoes, considering all the hazards and difficulties - and a very tolerant wife (who also apparently had a good sense of humor). He dedicated one of his publications to her with the following lines, in fact:

"To helpmeet and campmate, ISABEL JAGGAR, Whose horse crushed her against a tree . . . /, Whose gloves fell into a red hot crack and burned up . . . /, Who slept in a lava tunnel beside the immortal remains of a desiccated billy goat . . . /, And loved it all."

A pioneer in his field, a snazzy dresser and a good sense of humor? Something any volcanologist would aspire to.

Earth Day Edition: Where on (Google) Earth # 200!

2010-04-22T10:03:00.000-04:00

Perhaps I was a little quick jumping on the answer for Callan's first WoGE, but I couldn't resist...a time-lapse series of shots of the Spirit Lake logjam was an excellent (and timely) choice, since the anniversary of the 1980 Mount St. Helens eruption is coming up (May 18th!). The logjam that's shifting its position in Callan's pictures was created when trees, downed by the eruption's lateral blast, were washed into Spirit lake by water displaced in the initial debris avalanche. They've been floating on Spirit Lake ever since, and as you can see in the photos, they tend to migrate.

I've decided to run the 200th Wo(G)E on Earth Day, since it's also the 40th anniversary of the first Earth Day. What better way to take advantage of the date than to use Wo(G)E to highlight the beauty and the geology we can find on Earth?

So in this edition, not only are you going to see a lovely scene as revealed by Google Earth...you're going to see four, in honor of the four decades of celebrating Earth Day. (Yes, I'm evil. Hahahahaha!) And they're not just pretty pictures, but also locations that are geologically and environmentally significant. So here's the deal: Find the coordinates for each location and take a stab at describing why it's geologically significant. First person to come up with accurate locations and a reasonable explanation for each gets to host the next edition of WoGE; if you don't have a blog, you're welcome to choose a location and I'll be happy to post it for you.

A hint or two: Pay attention to the scalebars; altitudes were varied to make the images more aesthetically pleasing. No two features are on the same continent, and a few aren't on continents at all. There's not any particular underlying theme here - mostly I've just tried to choose remote locations. Click on the images to view them full-size.

Because I've made this Wo(G)E a bit more time-consuming by adding multiple locations, I'm not invoking the Schott Rule. First one to four wins!

PS - I get a lot of spam, so my comments are moderated. Don't worry if your answer doesn't show up right away - I receive them all in the order that they were submitted, so your position in the race is preserved. Have fun!

Volcano Vocab #3: Tephra

2010-04-16T09:21:00.000-04:00

Today's volcano word is tephra, another term that's directly related to the Eyjafjallajökull- Fimmvörduháls eruptions going on in Iceland at the moment. Tephra ("teff-rah") refers to any fragmented material thrown from a volcanic vent during an explosive eruption. It comes in different sizes, all of which have their own names (just to make things even more difficult!)

Bombs or blocks are large rocks - 64 mm and greater in diameter (cobble to boulder sized; see the photo at left, which is an example of a really big bomb on a scoria cone on Mount Etna). Lapilli are smaller, from 2 mm to 64 mm (the size of the material underneath the bomb at left). Ash is any material smaller than 2 mm, and is one of the main constituents of a volcanic eruption column, such as the one that's disrupting air traffic over northern Europe at the moment. Volcanic ash is composed of fragmented glass, rock, and phenocrysts (crystals), unlike the ash you get from fires (which is mostly carbonized organic material).

The other things that make up an eruption column are typically gases (including water vapor), ambient air that's been entrained and heated, and some lapilli and bomb-sized particles. Some recent news reports have been saying things like "ash and smoke" to describe the Eyjafjallajökull-Fimmvörduháls eruption column, which is incorrect. There is no "smoke" in an eruption column, at least in the sense that most people think of it (as a byproduct of burning materials). The column appears to be smoky, but only because of the presence of the ash, which is generally some shade of gray or black.* (The photo below, from a February 2010 eruption of the Caliente dome at Santiaguito, is quite gray to begin with, but I can guarantee that it's not because something in the vent is burning.)

Tephra is a major hazard associated with volcanoes. Bombs tend to be more of a problem in the vicinity of a volcano, but as many people in northern Europe are finding out, smaller particles like lapilli and ash can travel much higher and farther. Ash from a powerful eruption can reach the upper atmosphere, far higher than airplanes can fly; and because glass makes up a good portion of those ash particles, any plane that does fly through an ash cloud risks sucking glassy particles into its engines, where the glass can melt and re-solidify. This is bad - it could mean total engine failure, which is what happened to a flight over Alaska in 1989. No sane pilot is going to fly a plane into that.

So if you're stuck waiting for a flight to or from Europe, just remember: it's a lot better than risking a plane crash. And you can probably look forward to some spectacular sunsets.

*Okay, maybe some lichen is getting toasted, but that still doesn't mean you can call ash "smoke".

Volcano Vocab #2: Jökulhlaup

2010-04-13T09:26:00.005-04:00

Today's obscure volcanologically-related word is jökulhlaup ("yer-kul-hloyp", "YO-kel-yawp" and "yo-kul-h-loip" in varying pronunciations), which is an Icelandic word for glacial outburst floods, both of water and lahars, formed when a subglacial eruption occurs. The water for these floods is formed when heat from those eruptions melts glacial ice, forming lakes that eventually become unstable enough to break through channels in the base of the glacier and flow out from underneath it. (Apparently the word can also refer to flooding caused by geothermal heat rather than a subglacial eruption, but since it's hard to see what's going on under a glacier in the first place, I wouldn't be too picky about the generation mechanism; suffice to say that some sort of volcanic activity is involved.) To give you an idea of what an unstable subglacial lake would look like, here's a diagram from an excellent overview paper:

Figure 3 from Björnsson (2002), showing a stable sub-glacial lake (a) and (b) an unstable lake likely to form jökulhlaups.

How big are these floods? Here's a quote from the same paper, talking about jokulhlaups from formed by the Grímsvötn volcano under the Vatnajökull glacier:

Jökulhlaups from Grímsvötn have occurred at 1– to 10–year intervals, with peak discharges of 600 to 4–5×10⁴m³s⁻¹ at the glacier margin, a duration of 2 days to 4 weeks and a total volume of 0.5–4.0 km³.

Obviously, this is not a good thing to be in the way of. (By way of comparison, the mean discharge at Niagara Falls is about 1770 m³s⁻¹, or about ~~a quarter~~ one-thirtieth of the peak discharge during one of those floods.) I don't have any personal or public domain photos of a jökulhlaup, but the Global Volcanism program has some excellent photos from a 1998 event during an eruption of Grímsvötn.

This topic is quite relevant at the moment because of the recent volcanic activity in Iceland. While the fissure that's erupting at Eyjafjallajökull isn't in danger of melting much ice, there are several other volcanoes that are, such as Katla volcano under the Mýrdalsjökull glacier. Since roughly 10% of Iceland is covered in glacial ice, and the country has more than 30 volcanoes that have been active in the last 10,000 years, this is a major concern (see Ole Nielsen's post on jökulhlaups here).

If you're interested in more Icelandic geologic vocab, the USGS has an English-Icelandic glossary here. And here is the full citation for the Björnsson paper:

Björnsson, H., (2002), Subglacial lakes and jökulhlaups in Iceland. Global and Planetary Change, v. 35, p. 255–271. http://dx.doi.org/10.1016/S0921-8181(02)00130-3

UPDATE: Whoops! Totally forgot about this page over at Andrew Alden's About.com Geology. Lots more detail there!

Volcano Vocab: Guyot

2010-04-09T09:01:00.001-04:00

I don't want to steal the thunder of any of the Skepchicks (especially Evelyn, who's doing a fantastic job on the Geology Word of the Week feature), but I thought I'd start a bi-weekly post on obscure or specialized volcanology words. (Yes, it's really just an easy way for me to post, since I've got the Glossary of Geology sitting here and all I have to do is flip a page to get a post idea, but I'll try to include a little discussion along with the posts.) We'll see if I'm any more successful with this weekly feature than I was the last time.

So what's the first word o' the half-week? By dint of me opening to the glossary of a volcanology textbook and pointing blindly: Guyot!

A guyot ("gee-oh") is basically a flat-topped seamount, or underwater volcano. The glossary in Bardintzeff & McBirney's Volcanology (2000) adds a bit about why it's got a flat top:

A submarine volcano with a flat top produced by wave erosion before the island was submerged.

A guyot is one of the stages in the life cycle of an ocean island volcano, and the form occurs when a volcano is no longer actively growing and unable to replace what is lost to the erosive force of wind and waves. Here's a diagram to illustrate:

(This came from a powerpoint someone gave me a while back, and I don't know where they nabbed it from - looks like a textbook. If anyone recognizes it, let me know and I'll put in an attribution!)

Unfortunately, it's a bit hard to show off a photo of a guyot, since they're generally underwater. Here's something that looks similar, however, from Hawaii's Big Island. These photos were taken somewhere along Rt. 11 (Mamalahoa Highway) on the way to Punalu'u Black Sand Beach and Ka Lae (South Point). I remember that there was some discussion going on about guyots, but I'm not sure if these are the real item. Does anyone else know if these are 'stranded' guyots?

Poseidon would be flattered

2010-04-07T10:13:00.000-04:00

(A little diversion this week from Santiaguito topics; I don't want to feel like I'm beating the subject to death. Plus I wanted to try out this ResearchBlogging thing...)

Every week the volcanology folks here try to get together for a paper discussion of some sort, and this semester's theme is basaltic volcanism. Not exactly my area of expertise, but I decided to volunteer to lead the discussion last week with a paper that recently came out in Geology: "'Poseidic' explosive eruptions at Loihi Seamount, Hawaii" by C.I. Schipper, J.D.L. White, B.F. Houghton, M. Shimizu, and R.B. Stewart.

First, a little background on Loihi. This seamount, which lies about 35 km off the southeast coast of the Big Island, is the youngest volcano in the Hawaiian chain, although it will be at least another 10,000 years before it actually reaches the surface and starts developing black sand beaches for tourists to toast themselves on. Loihi has a summit caldera with cones and pit craters, and its eruption style varies from explosive (the subject of this article) to effusive (pillow lavas, which are mentioned in the discussion about vesicularity). When I first came to grad school, I would have thought of a submarine eruption as passive extrusion of pillow lavas, similar to the videos you can see on NOAA's Ocean Explorer website. This isn't always the case, however. While it's been fairly obvious that volcanoes just reaching the ocean's surface can erupt in an explosive and spectacular fashion, it hasn't always been clear that underwater volcanoes are capable of the same thing.

Schipper et al. review the traditional thinking on the process of submarine explosive eruptions: something like a Strombolian bubble burst, where slugs of gas exsolve from the magma and pop at its interface with the atmosphere (or seawater, in this case), throwing out little blobs of spatter and ash. This is a hard interpretation to test, however, if you can't observe the volcano erupting, or get hold of the eruptive products. Schipper et al. set out to do just that at Loihi, and made some interesting observations & interpretations. Their main conclusion is that the particular eruptive products they were examining were produced by thermohydraulic explosions (a kind of magma-water interaction), and not explosive fragmentation (magma being blown apart by rapid gas expansion).

To begin with, the lapilli (lava chunks smaller than 6.4 cm but larger than 2 mm) were quite vesicular - up to 40% - unlike the pillow lavas that make up the surface they were found on. The vesicles were also small, mostly spherical and not interconnected. Interconnected vesicles in a lava implies that there was a network through which gas could flow (sometimes called "open-system" degassing, where gas is moving independently of the melt); the lack of connectivity in the Loihi lapilli implies that there was "closed-system" degassing, where gases exsolve and form bubbles in the melt, but remain "coupled" to the melt and move with it. Schipper et al. suggested that the magma moved too quickly to allow coalescence, and that the bubbles formed in the conduit rather than at the magma-water interface.

Next to examine the issue of fragmentation....One mechanism that is often invoked for breaking up an erupting melt is explosive fragmentation, where gas in the melt becomes overpressurized relative to the outside atmosphere (as in when a gassy magma reaches the top of a conduit) and explodes. Schipper et al. note that this wouldn't work at Loihi, however, because at the 7.3 MPa pressures found 700 meters below sea level, the CO2 in the vesicles would be a supercritical liquid, and not capable of expanding fast enough to fragment the melt. (In addition, they suggest that the low viscosity of the basaltic melt would also allow rapid bubble expansion without fragmentation.) So how did these particles get fragmented? The authors point to a kind of hydromagmatic process called thermohydraulic fragmentation, which has to do with the interaction of hot material and water. In this process, water coming into contact with hot melt flash-boils and expands enormously, and the force of the steam expansion deforms and fragments the melt.

The authors suggest that thermohydraulic fragmentation provides enough initial energy that the overpressured-gas fragmentation can then take over above the level of the vent. This is an interesting idea; if it's true, how much of the fragmentation contribution comes from each process? The smallest particles that Schipper et al. examined (see Figure 4a-b, Schipper et al. 2010, at left) showed signs of having been produced by thermohydraulic processes (fewer interconnected vesicles, fracture surfaces that weren't bounded by vesicle walls, etc.), but the larger lapilli seemed to have been broken up following expulsion from the vent, which implies that thermohydraulic processes may be limited to the region below the vent. Additionally, there's the question of how representative the samples were; the study retrieved them some years after the eruption took place, and there's no telling how much was carried off by currents or other reworking processes. (Plus it can't be easy to sample something that's 3,000 feet down, since you have to use a submersible to get there. I would have liked to see the authors these as limitations, however.)

The figure at right (Figure 3d, Schipper et al. 2010) provides a good summary of what the authors think is going on: quickly-moving melt exsolves gas and develops vesicles that are unable to coalesce, so they remain spherical and isolated in the melt. When the melt reaches a point somewhere below the vent, it interacts with seawater in thermohydraulic fragmentation (samples represented by white circles in the figure), which then provides the energy to help initiate explosive fragmentation (the dark gray circles, which represent lapilli and bombs in their samples that were not formed by hydromagmatic processes).

The discussion group pretty much all agreed that they liked this paper for both writing style and conclusions, but had some issues with introducing a new bit of terminology to describe explosive eruptions. I have to agree; the term 'Poseidic' does have a basis for distinguishing these eruptions from subaerial ones (based on being underwater, having coupled volatile exsolution, and a particular combination of textures in its tephra), but you could reasonably also call this a 'submarine violent Strombolian' or 'submarine subPlinian' eruption. Still, distinguishing the style as an end-member is a wise choice, given the range of behaviors that volcanoes can exhibit, and the name might just stick. (Loihian is a suggested alternative, although that would come with spelling and pronunciation issues AND would be inaccurate in a few thousand years.)

Schipper, C., White, J., Houghton, B., Shimizu, N., & Stewart, R. (2010). "Poseidic" explosive eruptions at Loihi Seamount, Hawaii Geology, 38 (4), 291-294 DOI: 10.1130/G30351.1

Amazing natural resources in south-central Utah

2010-04-01T11:22:00.000-04:00

Some neat news has come out of the Marysvale Volcanic Field in southwestern Utah (one of my stomping grounds!) about a very recently reactivated hydrothermal system in the Marysvale Canyon. According to an interview with specialist H. McClintock, prospecting in the vicinity of Belknap (five miles north of Marysvale, Utah) has revealed some pretty interesting features that certainly weren't there when I visited last summer.

"We've come across some darn confounding stuff," says McClintock, who was reached for comments earlier today. "We thought that the hydrothermal alteration in the area had pretty much ended, since the Marysvale field has been inactive for the past 20 million years or so, but we've been seeing springs with high levels of hydrogen citrate and saccharose popping up all over the place, not to mention the streams of ethanol. Large drainage sinks have even started to form. We've decided to call the two biggest ones Aquavitae and Burgoo, although we'll have to wait to get the names officially registered."

When asked about potential environmental concerns of the increased hydrothermal activity, McClintock stated that a number of unusual phenomena have been noted in the local flora and fauna. "Local veterinarians have reported an increase in amelogenesis imperfecta, particularly among bulldogs, and there have been complaints that chickens are laying semi-solidified eggs. In addition, one of my crew found an odd tree that seems to be producing small cylindrical fruit consisting primarily of cellulose acetate and Nicotiana tabacum. Folks are getting a mite concerned." McClintock went on to mention that there has been a spate of thefts lately, resulting in a dearth of short handled shovels, axes, saws and picks, and - oddly - socks, forcing his crews to wear the same pair of socks for days on end. "Let me tell you, it's getting pretty ripe around here, although the weather seems to help a bit. Sunny every day, no wind, no snow, no rain - almost paradise. It's not good for keeping folks on the job, though - I keep finding my guys napping in boxcars all day."

McClintock is otherwise fairly excited about the potential for new hydrothermal alteration minerals in the area, since older deposits have been found that contain alunite, jarosite, and gypsum (see the reference below for more information - don't forget to check out the original article!). Gypsum, of course, is essential for building materials like drywall, while alunite is a main source for potash, used in the production of explosives, glass, soap, and soil fertilizers. This discovery also has the potential to repopulate the former mining communities in the area, which have suffered badly since the mines they were built around were abandoned due to lack of production. I'd like to see folks returning to the area, too - it's really beautiful, and well worth the trip if you're ever in that part of Utah.

To close, I'll leave you with another of the photos that was taken along the drive through Marysvale Canyon. The very field area that McClintock is talking about is right in the background there, behind the coconut. (We didn't leave the coconut there, although I'm sure it would have done well with the lemonade springs and cigarette trees.)

References:

"New prospects in the Marysvale Volcanic Field excite economic geologists", The BRCM Hobo, April 1 2010.

Rowley, P.D. et al., 2002, Geology and Mineral Resources of the Marysvale Volcanic Field, Southwestern Utah. Field trip guide, GSA Rocky Mountain Section Meeting, Cedar City, Utah, May 6 2002.

Accretionary Wedge # 23: What are you working on?

2010-03-26T20:59:00.000-04:00

The latest installment of the Accretionary Wedge is being hosted by Ed at Geology Happens, and here's the question of interest:

This AW is to share your latest discovery with all of us. Please let us in on your thoughts about your current work. What you are finding, what you are looking for. Any problems? Anything working out well?

My current work is a bit varied for a volcanologist, I'll have to admit. I'm busy mapping features on the Santiaguito lava domes after our trip down there last month - lots of time on Arc, which for once is behaving itself. But I'm also working with the samples I collected from fumaroles on that trip, looking for alteration minerals. This is requiring me to learn quite a bit about clay minerals, and how to prepare samples and run them on an X-ray diffractometer (XRD). I haven't done lab work since undergrad, and that was mineral separations for argon dating; clay prep is a bit easier, but takes longer, so I've only run one sample so far.

The results? Well, mostly the XRD seems to be picking up volcanic glass (from ash), because it's showing the same pattern that you might get just from running the glass slide. A smear slide did produce some interesting peaks, but I haven't had a chance to evaluate them yet (and unlike our clay mineralogist, I don't have d-spacings memorized!) This is only one sample, however, and I have high hopes for the rest. If the XRD angle doesn't work, I'll probably be spending some time (and money) on the dentistry school's scanning electron microscope (SEM), looking at particle morphology.

On the theoretical front, I'm getting ready to visit Los Alamos National Laboratory this summer, and learn how to use a finite element heat and mass transfer code called FEHM. The code is designed to model heat and fluid flow in hydrothermal systems - magmatic in particular - and I'm hoping to be able to apply it to modeling the hydrothermal system in a lava dome. Not Santiaguito - the domes there are too complex to model directly - but hopefully by the end of my research, I'll have developed a new generic model that will help explain how water moves through lava domes. This is no small task, and the thought of learning both the code itself and the thermodynamics behind it is fairly daunting. My committee seems to think I can do it, though, and I trust them - but it's going to be an enormous investment of time and effort. Then again, what PhD isn't?

So that's the skinny on the short and long term. This is the first real chance I've had to dig into some data, and exciting things are ahead!

Video Friday

2010-03-26T09:08:00.002-04:00

Still waiting to hear on some info for the next Santiaguito Observatory post, but in the meantime, here's a neat video to keep your attention: A view of an eruption filmed with a Forward-Looking-Infrared, or FLIR camera. (These are the cameras that you sometimes see on ghost-hunting shows when they're trying to find "cold spots", or what you might use to look for heat leaks if you're evaluating your house for heating efficiency.) Enjoy - espectially BHC, who requested it!

This is a "double" eruption of ash and gas filmed in March of 2009 from the Santiaguito Observatory. The FLIR video converter has sped it up for some reason, so it's about 12 times faster than the actual eruption, but you can always pause it and advance it slowly if you'd like to get the full effect. In FLIR video, the warmer colors (white, yellow, and orange) indicate higher temperatures, and the cooler ones lower temperatures. The highest temperature in this video is about 150C (although this can vary due to atmospheric and distance effects, so it's not an exact temperature).

(Sorry for the poor resolution - Blogger's video tool has gotten worse, for some reason.)

The Santiaguito Volcano Observatory

2010-03-19T20:19:00.002-04:00

It's Friday! Which means picture day, because pictures are easy and fun. I thought - as a lead-in to a fundraising project I'm starting, and which I'll talk about in the next post - that I'd give you all a tour of the Santiaguito Volcano Observatory. I've been there twice, on my last trip to Guatemala and for a couple of days on this year's trip. After five days of camping next to an active lava dome complex, this is pretty much the lap of luxury. Beds, electricity, running water - heaven! Plus it's set in the middle of a lovely coffee plantation, and the views are incredible.

Seriously, you can't compete with this for a first-thing-in-the-morning vista. You do have to get up early to see it - things cloud in by about 10 in the dry season, and probably even earlier in the rainy season (if you can see it at all). This view is looking northwest toward the cone of Santa Maria and the Caliente dome of Santiaguito. In the foreground is the Observatory's weather station, the front door, and a nicely informative sign.

See? Location and elevation. The Observatory is located on the land of one of the local fincas, ~~which is owned by~~ sells to Starbucks. ~~The building, water and electricity are (if I'm remembering correctly) all~~ The land was donated to INSIVUMEH, who built the observatory, and visitors who stay there pay a small fee for the drinking water and cooking gas that they use. There are usually two or three INSIVUMEH observers there full time - they have bedrooms and a nice little kitchen - and there are bunks for visiting scientists.

The Observatory's capabilities are pretty limited, however. The observers have been working there for years and know a lot about the volcano, but they're not academic scientists, and they don't have much equipment to speak of. Eruptions at Santiaguito are watched through the north-facing window in this photo, and reports are radioed back to Guatemala City and recorded on the typewriter. There's a pair of binoculars for closer observations, since it's a pain to drive much further toward the volcano from here, but that's mostly it.

The trusty (but noisy!) typewriter. If you see a report on Santa Maria in the Global Volcanism Program's newsletter, it was written up here first. There's no internet access at the Observatory, so whatever they want to report has to go out by radio or cell phone. They're working to change that, though - more on that later.

My favorite part of the Observatory! This is part of their rock collection, and a scale model of Santa Maria and the domes (made with actual rock and ash from the domes). If I was watching a volcano and had my view rained out for half the year (and a good bit of the clear days), I'd totally make one of these.

Another view, first thing in the morning. All the plants in the foreground are official Starbucks coffee plants, which are apparently unaffected by being ashed on every once in a while. (The finca office will sell you ground coffee for considerably less than Starbucks, and it's delicious. Probably because it hasn't been burned, which SB seems to like to do for some reason. Oddly enough, most Guatemalans don't drink coffee from the fincas - either they can't afford it, or they prefer the instant kind. Go figure.)

Our dual FLIR-video camera setup.Watching eruptions with a thermal camera is amazing, because you can see how the thermal currents rise in an eruption column (even when there's no more material coming from the vent).

And you get to see things like this - the top of an eruption cloud being sheared off by the wind. The wind patterns around Santa Maria have regional trends that change with the season, but locally they can change day by day. Eruptions occur at Santiaguito every few hours, so there's a near constant supply of ash to the areas surrounding the volcano. On the most recent trip we were fortunate enough to avoid having to deal with much ash (only a little on the first day), but people who live and work on the fincas and the Xela area have to put up with it all the time. Imagine having all that ash in your coffee!

Looking backward: Past eruptions at Volcán Santa Maria

2010-03-15T10:09:00.004-04:00

On our way to visit the Santiaguito Volcano Observatory, Gustavo Chigna of INSIVUMEH (the Guatemalan equivalent of the USGS) was kind enough to take an afternoon off and show us some of the older deposits near Santiaguito. Our first stops were at an exposure of the air-fall deposit from the October 24, 1902 eruption of Volcán Santa Maria. This eruption was a devastating one, stripping the land for more than 50 km around the volcano, burying villages and fincas (plantations) in more than 3 meters of ash, mud and rock, and killing more than 7,000 people (the exact number will probably never be known). The area had already experienced months of earthquakes prior to the eruption, and activity at the crater formed in Santa Maria continued for weeks afterward.

This location is about 4 km from the volcano. The 1902 air-fall deposit here is more than 2 meters thick (the photo is only showing the top bit, and Gustavo is standing a few meters behind the outcrop, so the sense of scale is a bit wonky. The big clast in the center is about fist-sized, though.). This fall deposit contains a mix of lithics (old and new lava and country rock) and pumice, and what's really impressive is that many of the lithics are the same size as the pumice (up to 15 cm). Generally, in a fall deposit the material will have had the same terminal velocity, which means the mass of the pumice and lithics should be roughly equal. Because pumice is much less dense than lithics, this usually means that the lithics are much smaller than the pumice. Possibly the lack of difference in clast sizes here has to do with the proximity to the volcano; in other places that we stopped, the pumices were definitely larger than the lithics.

The view from this location was pretty spectacular, and it highlighted the deposits from the November 2, 1929 dome collapse. Here you can just see the summit of Santa Maria, and the El Brujo and other domes in front of it. Brujo is the dark green dome farthest to the left, and the hummocky low hills in front of it ~~are~~ may be the result of that 1929 collapse. Hummocks are a classic sign of a debris avalanche of some sort, and can be seen in places like Mount St. Helens and Mount Shasta. ***Note: After speaking with Rudiger Escobar, a Santiaguito expert and fellow volcanologist (see the comments section), I wanted to note that the hills pictured here probably have more to do with lava flows coming off of Brujo than older collapse deposits, although some portion of them may be collapse remnants. It's also possible that I have faulty notes, as the conversation was mostly being conducted in Spanish at the time, and my Spanish skills are limited.

After a bit of backroad driving around the fincas, we reached the Rio Tambor, which was the site of many deaths in the 1929 dome collapse. The 1929 event, in which more than 3 million cubic meters of the lava dome collapsed, was mostly described by foreign geologists who interviewed survivors. Their accounts tell of glowing rains of ash and rock; boiling mudflows in the rivers covered with rafts of glowing rock; a blast that rushed back toward the volcano after it blew down the river valleys, scouring the south side of tree trunks; and people suffocating on gases and hot air. More than 3,000 people were killed, mainly because they were on the fincas for a religious holiday rather than in their villages. Sadly enough, this was a very minor dome collapse by volcanology standards (a large one might be in the hundreds of millions of cubic meters, such as those at Soufriere Hills on Montserrat).

The coffee plantations that were destroyed in 1929 are no longer here, but the new ones are beginning to encroach. Frankly, I'm not sure I'd want to spend my days working in an area where there are outcrops like this:

These photos are looking east across the Tambor at a mudplain created by lahars, and at the 1902 deposit (the white strip at the base of the cliff) overlain by block-and-ash flow and lahar (volcanic mudflow) deposits. Here the 1902 deposit is about 2 meters thick, and overlain by a thinner gray ashy deposit (perhaps from the 1929 collapse, although it hasn't been well studied and it wasn't clear if that guess was right). The upper blocky deposits are probably post-1929, and consist of a mix of lahar and block-and-ash (pyroclastic flow) leavings.

It was a bit difficult to get a scale into this picture, but the cliff is about 10 meters high, and the bigger boulders at the base are roughly the size of me. This is an interesting photo because it shows a very distinct division between two deposits. What we ended up discussing at this site was what kind of deposits these were, and how to tell them apart. Both block-and-ash flow deposits and lahar deposits look similar at first glance: very poorly sorted, with a clast size range from ash (< 2 mm, in the matrix) to boulders (> 25 cm, supported by the matrix). Both deposits are matrix-supported and both have a bit of a mix of angular and rounded clasts.

So how to tell them apart? One clue might be the angularity of the clasts; block-and-ash flows tend to be a bit more violent in terms of knocking rocks around, and they're dry, which means no muddy cushion for the rocks like a lahar might provide. But what happens if the block-and-ash flow goes down a river (like here)? It could become a lahar, which brings up all sorts of messy discussion about naming conventions. A better indicator of a block-and-ash flow would be the lithology of its clasts; lahars will pick up anything in their path and tend to have a big mix of rock types, while block-and-ash flows tend to be monolithological. Again, however, if a block-and-ash flow travels far enough, it may pick up enough clasts from other places to confuse this.

As it turns out, there is one sure indicator that you've got a lahar deposit, and it's not always easy to find (or present). Because a lahar is a wet flow, it will contain bubbles. When the lahar stops, sometimes those bubbles are unable to rise through the muddy liquid and are trapped; when the deposit dries out, the bubbles leave little spherical cavities in the fine-grained matrix. These are really hard to see and it's easy to debate what you're seeing if you're not sure.

So what was the verdict for these deposits? Based on a bit of ~~arguing~~ discussion, we decided that we were fairly sure we saw bubbles in the lower deposit, but that the upper one had more indicators of a block-and-ash flow deposit. So at this outcrop, we have about 4-5 meters of visible lahar deposits overlain by about 5-6 meters of block-and-ash flow deposits. Needless to say, this would not have been a fun place to have been standing for either event. In fact, Gustavo mentioned that very few people will come down to this area after dark, because some of the victims of the 1929 collapse are thought to haunt the riverbed. Having been down there in the evening, I can attest that it does get a little creepy when it's dark, and it would certainly be easy to turn the jungle sounds into the moaning or wailing of ghosts. Better not to stay there too long, ghosts or no ghosts; it is a channel filled with lahar deposits, after all.

A Guatemalan Lago Como: Lago de Atitlán and its volcanoes

2010-03-09T14:20:00.001-05:00

Aldous Huxley described Lake Atitlán as "Como with the additional embellishment of several immense volcanoes. It really is too much of a good thing." I completely disagree on the "too much" part, because Atitlan is stunning (and, in my opinion, the addition of volcanoes gives it a leg up on Lago Como!)

At the end of our field work, and after a brief trip to the Santiaguito Volcano Observatory (more on that in the next post!) we took the Pan-American Highway (CA-2) through the mountains to Lake Atitlán. Atitlán is a ~20 km wide caldera in the Guatemalan highlands that was formed by the Los Chocoyos explosive eruption around 85,000 years ago (although activity began 11-12 million years ago). Three stratovolcanoes (Atitlán, around 10,000 years old; Tolimán, a bit younger than 40,000 years; and San Pedro, which stopped erupting 40,000 years ago) have grown on the southern margin of the caldera, partially infilling it and jutting out into the caldera lake. The last recorded activity was pyroclastic flows, lahars and explosive eruptions in the 1850s at Volcán Atitlán, although historical records for this volcano date back to the 15th century; the volcano is still considered active. The lake itself is supposed to be the deepest in Central America, and may be 340 m deep or more. An earthquake that occurred in 1976 seems to have breached the lake at some place, and the lake level has been slowly dropping since then. (Ole Nielsen at olelog has a great post with more in-depth info on the caldera, and Wikipedia's article isn't too shabby.)

Here's a Google Map to get you oriented. Volcán San Pedro is the farthest to the left, Tolimán is the northernmost of the paired cones and Atitlán is the southern one.

View Guatemala Volcanology in a larger map

We had time for visits to San Pedro La Laguna and a boat ride to Santiago Atitlán, and it was a great chance to do some relaxing sightseeing. I've seen some articles recently about the bad aspects of visiting Atitlan - they claim that the lake smells, is sludgy and brown, surrounded by robbers and banditos and all sorts of other nasty things. Well, I don't know what lake they were visiting, but I found very little of that to be the case. True, the lake is contaminated with bacteria from sewage and farm runoff, and I wouldn't recommend drinking the water, eating fish from it or going swimming, but there wasn't a bit of sludge in sight when I was there:

The water was perfectly clear the whole time we were on the boat, and you could see the bottom for a long ways out. (There have been some nasty algal blooms recently, which no doubt account for the warning about staying out of the water, but we didn't see anything visibly yucky on the way from San Pedro to Santiago.)

As for getting to the lake, there is one road (I'm not certain which) where bandits have pretty much made a business out of stopping vehicles and robbing people. It's fairly easy to avoid this road, however, and we had no problems despite being a bunch of gringos in a big shiny SUV. (No problems with people, anyway. The last bit of the road into San Pedro, which is basically switchbacks down the inside wall of the caldera, is crazy curvy, and not a bit of fun if there are buses on it with you. You can make the turns, but the buses can't, and it's impossible to see around the corners on the switchbacks. Drive really slow and honk a lot to let the bus drivers know you're there, because otherwise they'll run you off the road.)

In San Pedro, we stayed at the Hotel Mikasa, which is very nicely appointed (hot showers without exposed electrical wires!) and has a great European-Spanish restaurant on the roof (I definitely recommend the paella.) San Pedro is a bit of a hippie town - there are a lot of transplanted gringos and massage parlors (real ones) and solar-powered hot tubs - but it's pretty quiet, and has some interesting shops. And a great view first thing in the morning:

Santiago Atitlán has a much bigger population of the native Mayan groups, but it seems to be a major stop on the tourist route, because the main road is pretty much lined with shops and crawling with loud, clueless Americans. (It took me ten minutes of waiting to get a photo without a tour group in it!) The shops have some beautiful textiles, however, and there seem to be quite a few local artists who sell their work.

The boat ride was fun, although if there had been any more people in there I think the sides would have been about an inch above the water. Talk about a low rider! The boat service is fairly reliable, though, and only costs about five dollars for a two-way trip.

It was fun to go shopping there, but I'm sure we would have seen much more interesting things if we'd had more than an afternoon. Alas, we had to drive back to Guatemala City later that night, so we didn't have the opportunity for exploration. The views on the boat ride, however, totally made up for the short trip:

My recommendation is that Lago de Atitlán is definitely not to be missed. The smaller towns like San Pedro and Santiago Atitlán are difficult to get to but worth the trip, and the larger ones (like Panajachel) have a lot to offer as well. And they're all a boat ride away from each other!

Close to home: The 2010 Ed Roy Award

2010-03-07T12:08:00.002-05:00

Some great news from Geospectrum - the latest Ed Roy Award winner is Jason Pittman, the lead science resource teacher at Hollin Meadows Elementary School in Alexandria, VA. This has me completely excited, because Hollin Meadows was the first elementary school I attended, and it's literally steps from home. It's a math and science focus school, and it's one of the first places I started getting excited about geology. (I even remember drawing volcanoes on one morning journal exercise...)

The Hollin Meadows website has a great section devoted to their science lab, and I'm sure Mr. Pittman had a hand in it, since he's also a top web designer. Have a look!

Here's a little about the award from AGI:

Given annually, the Edward C. Roy, Jr. Award recognizes one classroom teacher from kindergarten to eighth grade for his or her leadership and innovation in earth science education. This award is named in honor of Dr. Edward C. Roy, Jr., who was a strong and dedicated supporter of earth science education. Mr. Pittman will be presented with the Edward C. Roy, Jr. Award at the 2010 National Science Teachers Association National Conference in Philadelphia, Pennsylvania. Other finalists for the 2010 award are Greer Lynn Harvell of Clifford C. Meigs Middle School in Fort Walton Beach, Florida, and John Schaefers of Ingomar Middle School in Pittsburgh, Pennsylvania.

They haven't updated the main part of their website yet, but the Ed Roy award page has some more info about applying, as well as past winners. If you know anyone who teaches K-12 earth science and you think they're doing a stellar job, I encourage you to get them to apply for this - it's a great opportunity for recognition!

Everyone at Hollin Meadows must be really proud of Mr. Pittman - and I am, too, even though I only have a very loose connection to the school now. It's been a good few months for them - they also hosted the First Lady in November, and had a chance to show off some of the extensive flower and vegetable gardens that make up an important part of their science program. Congrats to Mr. Pittman and Hollin Meadows!

Watch your step: Field work on lava domes

2010-03-05T15:49:00.000-05:00

I suppose I've left you all hanging long enough, so now it's time to show off the first batch of photos from Guatemala. The trip started out in Guatemala City, where we loaded up our rental car and drove to Quetzaltenango (known as Xela or Xelaju to most people). From Xela we drove to a finca, or farm/plantation, and then spent three hours hiking through jungle, over landslide scars and down rocky riverbeds. It was a tough, messy hike, although we were lucky enough to have porters go first and cut a path through the brush with machetes. (This did have its drawbacks, though, since the average Guatemalan is shorter than me, and we had some pretty tall people in the group. There was a lot of stooping and some crawling, which isn't all that fun when the foliage is covered in volcanic ash.)

Eventually, we made it to the campsite. How would you like to wake up to this view every morning?

This is the El Brujo dome, the westernmost and youngest dome in the Santiaguito dome complex. Don't be fooled by the lack of scale in the photo - this shot was taken from a distance of ~ 400 m from the base of the dome, which is roughly 300 m high. "El Brujo" means "the wizard" or "the sorcerer" in Spanish (all the domes have somewhat odd names, and there's not a lot of consensus on how they were chosen).The "back sides" of the western Santiaguito domes are abutted by an alluvial plain created from material washing off of Santa Maria and the domes. And this isn't just sand and pebbles; this is serious lahar deposits, which you get to hike across every morning before you even get to the domes. The deposits range in grain size from ash and sand to boulders the size of small cars. There was, predictably, a lot of tripping on the way to Brujo.

Tripping also happened because we stopped to watch this every so often. Eruptions with your coffee, anyone?

After crossing the alluvial plain, we climbed up the pass between Brujo and El Monje ("the monk"). This was pretty much like climbing over lahar deposits, only at a thigh-busting steep angle.

But once we reached the top, we were in a totally different world. El Brujo hasn't been active for several decades, and in that time enormous amounts of ash have accumulated on the top and flanks of the dome. Probably because of the May-October rainy season in this part of Guatemala, much of the ash is covered in vegetation - moss, grass, shrubs, even a few stubby trees. It's a cool landscape:

Enough ash collected in spots that there's a kind of sandy alluvial plain in between El Brujo and El Monje. It would make a good camping spot as long as it didn't get rained on.

The main attraction for me on the domes, however, was the fumaroles. And there were a lot of fumaroles - all down the divide between the two domes and well up onto their flanks, in fact. The fumaroles weren't much hotter than boiling - I could and did spend a lot of time poking my face into them - and release mainly water vapor. If there were any other gases, they were in small enough amounts to be undetectable and non-irritating, which was definitely a bonus. No one likes to do field work with a mask stuck to their face all day!

I got a nice set of samples from these and other fumaroles on this part of the domes, and hopefully I'll be able to find some clays in them. Clays in these fumaroles means that they could potentially be washing down through the void spaces and depositing in the domes, or even forming there initially. The low temperature of the fumaroles is also an ideal condition for clay formation - once the temperature gets over 200 C, you start forming other alteration minerals.

That's me on the right, contemplating how much I want a sample vs. the comfort level of sticking your face into the geologic equivalent of the spout on a boiling teakettle. I spent a lot of time with my glasses off to keep them from fogging up, which because of my nearsightedness required me to get even closer to the fumaroles. While I was pretty overheated by the end of that day of sampling, I did have lovely clean pores.

There were some great views of the other domes from El Brujo. This photo is looking roughly to the east at El Monje, La Mitad ("The Middle"), and El Caliente ("The Hot One"). The conical, flat-topped Caliente is the source of the regular eruptions that Santiaguito is known for (one of which appears in an earlier photo, and that I posted video of last year).

Having seen and heard more eruptions from Caliente, I'm no longer convinced that calling them "Vulcanian" is the best description. They're largely degassing explosions, with very little ash and almost no visible ballistics, and appear to be coming from a ring of small vents rather than a central larger one.

We didn't spend all our time scrambling around the domes; on the last day of field work some of us took time to examine the pyroclastic deposits and lava flows of Santa Maria, the main volcano that was responsible for the formation of the dome complex. Santa Maria last erupted in 1902, creating the huge crater that you see in the photo below. That eruption removed about 0.5 cubic km of material from the volcano's flank, and ejected something like 5 cubic km of material over the surrounding area. More than 7,000 people were killed, thousands of acres of plantations (mostly coffee) were destroyed, and Guatemala experienced famine and unrest for some time following the eruption.

This photo is a wonderful example of the "layer cake" model of a volcano - something that most volcanology classes will tell you is an inaccurate depiction of a volcano's interior. Apparently Santa Maria didn't get that message, because it's easy to see the fabulous layering in this view of the 1902 crater.

As we circled the flanks of Santa Maria, we encountered several outcrops of bedded pyroclastic deposits - in this case, several meters of air fall ash and pumice overlain by block and ash flow deposits (cobble to boulder-sized chunks of rock and pumice in an ashy matrix). These were under and overlain by massive lava flows, and they're probably older than the 1902 eruption by a few thousand years at least.

A chute made from massive andesite lava flows worn down by water. This would have been our route to get to the domes had we not chosen the jungle-and-landslide-scar path. It was fairly easy to climb up, but the thought of going downhill on polished lava with lots of ash underfoot and a 40-pound pack was somewhat terrifying.

On another lava flow closer to the El Monje dome, we found what my advisor described as "stretch marks" - places where the cooling lava flow pulled apart and left little stringy bits hanging in the crack (easiest to see next to the handle of the hammer and at the far right of the photo):

And, of course, we were rarely without views of the eruptions from Caliente:

In the next post I'll have more photos of the 1902 and 1929 deposits, as well as some shots from our visit to the Santiaguito Observatory. And a little bit about the shaking we felt - or rather, didn't feel.

Some better tsunami coverage

2010-03-03T09:35:00.001-05:00

I know there's been a general feeling of disgust in the geoblogosphere about the coverage of the recent Chilean earthquake and its associated tsunami. Fortunately, a few news channels have managed to get hold of geologists and actually listen to them properly. And hey, if it happens to have been my undergraduate advisor, even better!

This is a clip of my undergrad advisor (Dr. Chuck Bailey of the College of William & Mary) from WAVY News 10, the local NBC station for the Williamsburg/Hampton Roads/Norfolk area of Virginia.

Nice job, CB! I wish they'd consult geologists more often. Chuck also blogs about what's going on in the Geology Department at William & Mary - have a look or follow the feed!

Back in los Estados Unidos

2010-03-01T14:03:00.001-05:00

Just a quick note to let you all know that I'm finally back from Guatemala with samples in hand and only a bit of surface damage. (Much better than last time.) It was a really successful trip, minus the bits where we had to deal with driving around Guatemala, and I'm really happy that the field work went as well as it did.

I'm still in the process of unpacking and making up classwork, but I'll hopefully have some photos up in a day or two, as well as a bit about the work our field group did. I've also come back with a mission: INSIVUMEH, the geological survey in Guatemala, desperately needs help with equipment for the Santiaguito observatory, and I volunteered to see what I could do from this end, since they've done so much to help me with my research. Again, more on that in the next few days.

I've come back from this trip with a new appreciation for the difficulty of doing research on volcanic domes, a few bruises, and a lot of things to think about. And more blogging material, of course!

Essential reading for volcanologists

2010-02-24T09:00:00.000-05:00

One of the things I've found out since starting serious research in volcanology is that a lot - and I mean a lot - of the best texts are either out of print, expensive, or both. Fortunately there are enough people in the department that we have a fairly good selection of them - better than the library, anyway - although we're going to be in big trouble when certain folks graduate. (Either that or we're going to have to kidnap their collections.)

Anyway, being a bookish type, and having noticed the other book reviews that have come out on the geoblogosphere lately, I thought I would begin working my way through a list of the books that I've found most useful over the last year or so. Granted, I haven't used all of these extensively, but this will give me a good chance to refresh my memory on what I could be using. A lot of these texts combine general and specific subject matters, so it's a little hard to divide them up by specialty, but I'll try and go from really general to more specific.

Volcanism, 2003, Hans-Ulrich Schmincke
Fundamentals of Physical Volcanology, 2008, Parfitt and Wilson
Volcanology, 2000, Bardintzeff and McBirney
The Encyclopedia of Volcanoes, 1999, Houghton et al.
Volcanoes, 2003, Francis and Oppenheimer.
Pyroclastic Rocks, 1985, Fisher and Schminke
Volcanic Successions, 1987, Cas and Wright
Volcanology and Geothermal Energy,1992, Wohletz and Heiken (the full text of the book is available at this link)
Altered Volcanic Rocks, Gifkins et al.
Igneous Petrogenesis, 2007, M. Wilson
Atlas of Igneous Rocks and their Textures, 1982, MacKenzie et al.
Volcanoes of the World , 1994, Tom Simkin and Lee Siebert (Global Volcanism Program)
Monitoring Active Volcanoes, 1995, McGuire et al.
Remote Sensing of Active Volcanism, 2000, Mouginis-Mark et al. (eds)
Volcanoes, 1972, Gordon MacDonald
Ash Flow Tuffs, 1979, Charles Chapin (ed)
Volcano Deformation, 2006, Daniel Dsurizin (ed)
Introduction to Volcanic Seismology, 2003, V. Zobin
Volcanic Ash, 1985, Heiken and Wohletz
Volcanic Textures, 1993, Doyle and McPhie
Monitoring and Mitigation of Volcanic Hazards, 1996, Scarpa and Tilling
Volcano Instability on the Earth and Other Planets, 1996, McGuire
Fire and Mud, 1996, Newhall and Punongbayan
The Physics of Explosive Volcanic Eruptions, 1998, Gilbert and Sparks
From Magma to Tephra, 2001, Freundt and Rosi
Environmental Effects on Volcanic Eruptions, 2000, Zimbelman and Gregg
Volcanoes and the Environment, 2008, Marti and Ernst
Volcanic Degassing, 2003, Oppenheimer et al.
Kinematics and Dynamics of Lava Flows, 2005, Manga and Ventura
Mechanisms of Activity and Unrest at Large Calderas, 2006, Troise et al. (eds)
Caldera Volcanism, 2008, Gottsman and Marti
Fluid Motions in Volcanic Conduits, 2008, Lane and Gilbert
Earthquake and Volcano Deformation, 2010, Paul Segall

In most cases I've linked to Amazon, mostly because they do pretty decent summaries of content, but these books are often available straight from the publisher, or from independent booksellers (for a greatly reduced price). Bookfinder.com is where I start whenever I'm looking for an obscure book, although beware of inflated prices for out-of-print editions.

Volcanic clays

2010-02-20T09:00:00.001-05:00

Another big part of my PhD research concerns volcanic clays. Volcanoes are a really interesting example of multiple natural cycles operating at once - not only do they create new rock, they also break it down. This could be pretty quickly - blasting lava into ash in an eruption - or slowly, through hydrothermal processes. When you get a combination of hot rocks and water, you (eventually) get alteration minerals, and some of those include clays.

This is a major concern in terms of volcano stability. Clays are weaker than the rocks that they form from, and an informal term that volcanologists use for hydrothermally altered rock is "rotten rock". In some cases, the reduction in stability is a function of the clays themselves, which are layered minerals and thus likely to shear along particular planes; in other cases, the reduced stability is because of what clays do, which is block or absorb water. Clays are made up of layers of tetrahedral and octahedral structures, and depending on how those layers are arranged (and how many times the tetrahedra repeat in a layer), a clay can either act as a barrier to water, or absorb it and expand (these are known as "shrink-swell clays"). If a clay blocks water, it could create a slippery plane within a volcanic edifice, which would make it easier for the rock above it to fail and collapse. Kaolinite clays are an example of this. If a clay absorbs water and shrinks or swells, this constant movement could also destabilize the material above it (smectites ~~and~~ like montmorillonite are good examples here.)

But the dangers don't stop there. Clays, in a collapse of a volcanic edifice, can increase the runout of the debris or mudflow that may result; this occurred in Nicaragua in 1998 at the Castia volcano, when a hurricane caused part of an old lava dome complex to collapse, and the smectite clays that had formed in the domes from hydrothermal processes helped form a massive lahar that traveled more than 10 km. It's also a concern at a number of Cascade volcanoes, including Mount Rainier; even if the volcanoes haven't erupted in a long time, there are still active hydrothermal systems within their flanks, altering the volcanic rocks there to weaker materials. Multiple studies have attempted to map these alteration zones and determine where a collapse might occur based on the location and extent of particular clay minerals.

Further Reading:

Crowley, J.K., Hubbard, B.E. and Mars, J.C., 2003. Analysis of potential debris flow source areas on Mount Shasta, California, by using airborne and satellite remote sensing data. Remote Sensing of Environment, 87(2-3): 345-358.

John, D.A., Sisson, T.W., Breit, G.N., Rye, R.O. and Vallance, J.W., 2008. Characteristics, extent and origin of hydrothermal alteration at Mount Rainier Volcano, Cascades Arc, USA: Implications for debris-flow hazards and mineral deposits. Journal of Volcanology and Geothermal Research, 175(3): 289-314.

Opfergelt, S., Delmelle, P., Boivin, P. and Delvaux, B., 2006. The 1998 debris avalanche at Casita volcano, Nicaragua: Investigation of the role of hydrothermal smectite in promoting slope instability. Geophysical Research Letters, 33(15): 4.

Reid, M.E., Sisson, T.W. and Brien, D.L., 2001. Volcano collapse promoted by hydrothermal alteration and edifice shape, Mount Rainier, Washington. Geology, 29(9): 779-782.

Sheridan, M.F. et al., 1999. Report on the October 30 1998 rockfall/debris avalanche and breakout flow of Casita volcano, Nicaragua, triggered by Hurricane Mitch. Landslide News, 12: 2-4.

Wohletz, K. and Heiken, G., 1992. Volcanology and Geothermal Energy. Los Alamos Series in Basic and Applied Sciences. University of California Press, Berkeley.

Zimbelman, D.R., Rye, R.O. and Breit, G.N., 2005. Origin of secondary sulfate minerals on active andesitic stratovolcanoes. Elsevier Science Bv, pp. 37-60.

Dome collapses

2010-02-16T09:00:00.001-05:00

In light of the recent dome collapse at Soufriere Hills, I thought I'd expound a little on the subject, which is a major part of my research. Lava domes, if they last long enough, tend to go through cycles of growth and collapse. These can be relatively short, like the domes at Soufriere Hills or Mt. St. Helens (remember, a few years is short even on a volcanic timescale), or long, like at Casita volcano in Nicaragua or my own study area of Santiaguito. The collapses vary in volume: a smallish collapse might comprise a few million cubic meters of material (the 1929 collapse at Santiaguito was about 3 million cubic meters), but the collapse of an entire dome might be in the 100s of millions of cubic meters.

There are a number of reasons why domes collapse. One is gravity; domes can grow on steep slopes or overspill summit craters, which means that parts of them can become very unstable and simply collapse because of their own weight. Another trigger might be an earthquake, which can shake loose dome rock; yet another trigger might be an eruption, which could loosen or even blow up significant portions of a dome. (This could be what happened at Soufriere Hills; there have been some pretty spectacular Vulcanian eruptions going on at the same time as dome-building there.)

My research, however, focuses on how water can cause dome collapses over short and long timescales. In the short term, intense precipitation events (large storms or hurricanes) have been known to cause domes to collapse (especially at Soufriere Hills). This likely has something to do with water saturating the domes to the point where it can penetrate deep into hot dome rock, and either a) sealing in magmatic gases or b) sealing itself in and vaporizing in cracks and fractures. Either way means that pressure builds up in the dome and water can lubricate structural breaks, which reduce the stability of the dome. In the long term, a dome with an active and well-supplied hydrothermal system can form lots of clays, which are very weak and can also trap water. (Some clays even swell when they absorb water, which pushes dome rock around and destabilizes it that way.) This seems to be what happened when some old domes at Casita Volcano in Nicaragua collapsed and formed a devastating lahar, or mudflow of volcanic material.

What I intend to focus on at Santiaguito is why the domes there haven't experienced any major collapses in the 80 years they've been growing, and what part of the complex might be most likely to fail if a collapse did occur. This is going to involve looking at water-dome interaction in both the short and long term; I'm mixing in hydrology and clay mineralogy with my volcanology, and on this trip I hope to collect clay samples from the inactive domes in the complex. (I am not going anywhere near Caliente, the erupting dome, if I can help it; those videos of people standing on the rim during eruptions are just insane. I've met people who were at Galeras when it erupted in 1993, and I've heard enough about what can happen that I have no intention of putting myself in that kind of danger.)

Further Reading:

Barclay, J., Johnstone, J.E. and Matthews, A.J., 2006. Meteorological monitoring of an active volcano: Implications for eruption prediction. Journal of Volcanology and Geothermal Research, 150(4): 339-358.

Calder, E.S., Luckett, R., Sparks, R.S.J. and Voight, B., 2002. Mechanisms of lava dome instability and generation of rockfalls and pyroclastic flows at Soufriere Hills Volcano, Montserrat. Geological Society, London, Memoirs, 21(1): 173-190.

Elsworth, D., Voight, B., Thompson, G. and Young, S.R., 2004. Thermal-hydrologic mechanism for rainfall-triggered collapse of lava domes. Geology, 32(11): 969-972.

Fink, J.H. and Anderson, S.W., 2000. Lava domes and coulees. In: H. Sigurdsson, B.F. Houghton, S.R. McNutt, H. Rymer and J. Stix (Editors), Encyclopedia of Volcanoes. Academic Press, San Diego, California, pp. 307-319.

Harris, A.J.L., Rose, W.I. and Flynn, L.P., 2003. Temporal trends in lava dome extrusion at Santiaguito 1922-2000. Bulletin of Volcanology, 65(2-3): 77-89.

Matthews, A.J. et al., 2002. Rainfall-induced volcanic activity on Montserrat. Geophysical Research Letters, 29(13): 1644-1647.

Sapper, K. and Termer, F., 1930. Der Ausbruch des Vulkans Santa María in Guatemala vom 2-4 November 1929. Zeitschrift für Vulkanologie, 13: 73-100.

Sheridan, M.F. et al., 1999. Report on the October 30 1998 rockfall/debris avalanche and breakout flow of Casita volcano, Nicaragua, triggered by Hurricane Mitch. Landslide News, 12: 2-4.

Taron, J., Elsworth, D., Thompson, G. and Voight, B., 2007. Mechanisms for rainfall-concurrent lava dome collapses at Soufriere Hills Volcano, 2000-2002. Journal of Volcanology and Geothermal Research, 160(1-2): 195-209.

Voight, B. and Elsworth, D., 2000. Instability and collapse of hazardous gas-pressurized lava domes. Geophysical Research Letters, 27(1): 1-4.

Roughing it - Guatemala la segunda parte

2010-02-13T18:17:00.002-05:00

Yes, I've been hinting at some fieldwork that I'm going to do for the next two weeks - and it's back in Guatemala!

If you remember the posts I put up last year about my first visit, you'll also remember that quite a bit less science happened than I was hoping, thanks to some nasty little microscopic critter that found its way into my food. I really, really don't want to repeat that experience this year, so I'm going down armed with a supply of antibiotics and Gatorade powder. This year's trip is going to be a little more ambitious; we're planning a five-day hike to the lava domes at Santiaguito, and I'm going to be collecting as much clay as I can. (Why not rocks? Volcanic clay is my topic of interest at this volcano - more on that in subsequent posts.)

At any rate, I'll be out of touch for a bit, although I do promise to update when I can. In the meantime, I've scheduled a few posts about some of my subject matter, and volcanology in general. And there will be great photographs to show off when I get back!

A local waterfall in winter

2010-02-10T10:04:00.005-05:00

Of course, local for me means Niagara Falls. I took a trip up on Saturday to get myself outdoors for a little while, and while I'm pretty sure no important parts of me were permanently frozen, it was effing cold up there. (Not very snowy, though. It's pretty ironic that I moved away from the Washington DC area, and they're now poised to get more snow than Buffalo this year. I think Buffalo's at about 60 inches, and if DC gets another foot or so with today's storm, they'll have us beat. Not that Buffalo is the snowiest place in New York by any means - that's Syracuse. But I digress.)

One interesting thing I found out about Niagara Falls in the winter is not only is it cold, it's damp. This is a direct result of all the spray from the Canadian and American Falls. It looks like the US gets the worst the spray off Horseshoe Falls, since the prevailing winds blow from west to east. Anyway, it makes for a somewhat hazardous visit, because everything is covered with ice.

The ice gets really thick in places, and you can see how the layers were built up. This chunk came off a light pole. It's stratification on a vertical plane!

Quite a bit of the park on the NY side was closed off, presumably because it was so slippery and they didn't want people too close to the water.

A little artsy shot with a chunk of ice rime:

As it turns out, I have a habit of standing in almost exactly the same spots when I take photos up here. It's likely that this is just because those are the clear (and well-framed) shots, but it means I can show some neat comparisons between the winter and summer versions of Niagara Falls. As always, click to embiggen:

In the winter, because tourism is slow, the hydroelectric companies on both sides of the Niagara River restrict the water going over the Falls to about half of its full capacity (which means that around 50,000 cubic feet/second or 1,400 cubic meters/second). In the summer, somewhere around 10-25% of the flow is diverted, depending on the level of Lake Erie, which feeds the Falls.

The Canadian side really has the better views, but on the American side you get to wander around on Goat Island, which sits in between the Horseshoe (Canadian) and American Falls. Here's a couple of shots from the top of Goat Island:

Here's a brave little seagull and his favorite spot - I'm hoping the rock will be there when the ice melts!:

Looking upstream at both sets of falls:

And again:

It's pretty neat to see how things change by season. The icepack in the river gets pretty thick, so those Maid Of The Mist boats that you see going out the rest of the year are all beached, and no one goes down to the observation decks (and who'd want to get drenched in the middle of winter? Not me!)

I'll try to get a few more posts out this week, since I'm going to be in the land of sporadic internet access for the rest of the month. More on that later!

Blast from the past

2010-02-05T09:15:00.001-05:00

On Wednesday the volcanology lab groups here at UB had a discussion about basaltic eruptions, particularly at Paricutin and Jorullo volcanoes in Mexico. The first thing I was reminded of on hearing the name Paricutin was not a geological fact, but a childhood memory - one of watching Reading Rainbow, actually.

Reading Rainbow, if you aren't familiar with it, was one of the best children's shows out there. Sadly, it ended in 2006, but in its 23 year run, host Levar Burton and any number of celebrity narrators did wonders to keep kids reading and show them that books were not only worth their time, but fun and exciting to boot. Each episode was divided between book reviews and readings - sometimes by well-known celebrities like Julia Child and James Earl Jones, to name a couple - and Levar Burton visiting people and places related to the theme of the episode. It was one show that my parents were happy to let me watch any time it was on, and they'd usually try and find the books for me to read afterward. It's sad that it's no longer going, but hopefully reruns will still pop up on public television stations.

In fact, a few of those early episodes - reruns for me, since I wasn't around to watch their first runs - were responsible for starting me on a geologic path. I particularly remember one episode called Hill of Fire, in which the featured book talked about a volcano that suddenly appeared in a Mexican cornfield - Paricutin, of course. I thought this was totally fascinating, and probably asked my parents if we could have a volcano in our backyard, or something like that. And now that I'm in graduate school, I can look back on what I remember of that show and use it as a basic context for understanding the professional papers I'm reading. How cool is that?

Another episode talked about one of my favorite childrens' book series: The Magic Schoolbus. Who doesn't love Ms. Frizzle and her crazy bus? Of course, the book was The Magic School Bus Inside the Earth, which I'm sure I made my mother go out and buy for me right afterward. These books were a great introduction to science topics, because they gave you the facts as a part of a narrative. Sneaky! Plus it's always fun to see what clothing Ms. Frizzle is going to wear next. Personally, I want some of those jumpsuits for when I do fieldwork.

Not to mention Three Days On a River In a Red Canoe. It's not about geology, but it was my first intro to camping. I didn't do any serious camping until I was in college, but this episode definitely had me out in the backyard for a few nights that summer. I have yet to take a canoe trip, however...perhaps a goal for this summer?

Obviously, these aren't the only geology/outdoors-related children's books out there, but they are a few of my favorites - and I remember them after fifteen years or so because of Reading Rainbow.

Hooray!

2010-01-27T20:43:00.000-05:00

Quals are over and passed (pending some proposal rewriting and me promising to take a thermodynamics class in the near future). It's nice not having that stress hanging over my head - now I can relax and get some research done! (Not to mention getting back to blogging more often...)

Where On (Google) Earth #181

2010-01-19T20:14:00.003-05:00

Looks like I get to host the next episode of Where On Google Earth! Wo(G)E #180 over at Clastic Detritus turned out to be a tricky rotated image of the Farasan Banks, a huge coral reef complex off the coasts of Saudi Arabia and Yemen in the Red Sea. I don't know much about them beyond what I could dig up from a Jacques Cousteau quote:

"The wildest of all the reef complexes in the Red Sea … 350 miles long and thirty miles wide …. This demented masterpiece of outcrops, shoals, foaming reefs, and other lurking ship-breakers was created by societies of minute animals that have changed the aspect of our planet far more than man has yet been able to do."

Anyone out there a coral reef expert? At any rate, I'm sure you're all waiting for the next challenge. Here it is:

Click to zoom. No altitude or direction on this one, but hopefully there are enough clues for you to track it down. To win the round, you need to post the correct latitude and longitude in the comments below, along with a little commentary about what geological feature you're looking at. The winner gets to host the next round, or choose the location and ask someone else to host it if they're not a blogger.

To give any newcomers a head start on this one, I'll invoke the Schott Rule- you have to wait one hour after the post time to answer for each WoGE round you've one in the past. Good luck!

PS - If you want to see where Wo(G)E has gone in the past (and who's won it), take a look at Ron Schott's compilation in KMZ format!

Richter or not?

2010-01-14T11:27:00.006-05:00

Most of you have probably heard about the earthquake that occurred in Haiti on Tuesday. It's shaping up to be a huge disaster, especially since it occurred in an area that hasn't seen a major earthquake for centuries; when natural disasters haven't occurred within living memory, people become unprepared to deal with them. The poverty of most of the millions of Haitians who were affected has only made it worse, and it's going to be a difficult recovery for them. I encourage everyone to find a charity that will be providing aid (the Red Cross, UNICEF, Doctors Without Borders, and Direct Relief International are just a few) or donate blood through the Red Cross. Even a few dollars or a little bit of blood will help.

It's only natural that a lot of news agencies will report natural disasters, and especially large earthquakes. But over and over again, I hear even the best reports making the same mistake: using the phrase "the earthquake was an X on the Richter scale." A Google News search for "Haiti earthquake Richter" brings up more than 500 references to news articles that use that phrase. It might seem nitpicky, but it always annoys me when the media can't be bothered to use the correct phrasing to describe earthquakes - it's a small misuse of scientific terminology, but if you take a closer look at it, it's a significant one.

The Richter magnitude scale was developed in 1935 by Charles F. Richter of the California Institute of Technology based on measurements made of shallow earthquakes in California. Technically, the way it was developed means that it's the most accurate in California, and when using a specific type of seismograph; it's also not terribly accurate for very large earthquakes or distant ones. Scientists have since expanded on the methods Richter used, which now incorporate even more data that can be recorded about an earthquake. The USGS website about "Earthquake Magnitude Policy" says it this way:

"There is some confusion, however, about earthquake magnitude, primarily in the media, because seismologists often no longer follow Richter's original methodology. Richter's original methodology is no longer used because it does not give reliable results when applied to M> 7 earthquakes and it was not designed to use data from earthquakes recorded at epicentral distances greater than about 600 km. It is, therefore, useful to separate the method and the scale in releasing estimates of magnitude to the public."

As far as the USGS is concerned - and they're usually the ones reporting earthquake magnitudes to the media - the preferred method of referring to magnitudes is with moment magnitude. Again, the USGS says it pretty succinctly:

"Moment is a physical quantity proportional to the slip on the fault times the area of the fault surface that slips; it is related to the total energy released in the EQ. The moment can be estimated from seismograms (and also from geodetic measurements). The moment is then converted into a number similar to other earthquake magnitudes by a standard formula. The result is called the moment magnitude. The moment magnitude provides an estimate of earthquake size that is valid over the complete range of magnitudes, a characteristic that was lacking in other magnitude scales."

Moment magnitude is measured on a logarithmic scale - each step up is many times more powerful than the last. This means that the 7.0 earthquake that happened in Haiti is much more powerful than, say, the ~M 5 earthquake that I felt in Guatemala earlier this year. When talking about earthquakes, official reports nowadays (like the USGS press releases) say the earthquake had a "magnitude of X". This is not to be confused with earthquake intensity, which measures the strength of shaking at any particular location, and is determined mainly by the earthquake's effects on people and structures. (An earthquake rating a I on the Mercalli Intensity Scale would be so small that almost no one would feel it, while the Haiti earthquake would be a VIII or higher, with significant or total destruction and visible effects during the shaking.)

So the takeaway message is to be careful how you talk about earthquake magnitude. If the information is coming from the USGS, it's referring to moment magnitude, and not the Richter scale. Hopefully some of the media will eventually pick up on this, for accuracy's sake if nothing else.

The biggest bang for your buck

2010-01-05T16:42:00.001-05:00

Happy New Year! Having finally beaten the latest installment of the common cold, I'm back to blogging as I get ready for the new semester.

Recently there's been a bit of amusement among the geobloggers about an Paddy Power, an Irish betting website that's will take wagers on which volcano will erupt next with a VEI 3 or greater magnitude eruption. That in itself is amusing (and it would be an interesting way for grad students to fund their research, although I'm not sure it's legal).

Doubtless, however, the folks running (and looking at) this website don't know a whole lot about the VEI system that they're basing the bets on. VEI stands for Volcanic Explosivity Index, and it's a scale that was introduced by Christopher Newhall and Stephen Self in 1982. It was originally meant to be a way to estimate the explosive magnitude of past volcanic eruptions, and combines a number of criteria:

Volume of material erupted (also called ejecta or tephra)
Height of the eruptive column
Qualitative descriptions (i.e., "effusive", "explosive", "paroxysmal")
Classification (Hawaiian, Strombolian, Vulcanian, Plinian, Ultraplinian)
Duration in hours
The most explosive type of activity observed
Tropospheric (up to ~10 km) and stratospheric (~10-50 km) injection of material (i.e., did the eruption column reach these atmospheric levels?

Including both quantitative and qualitative criteria allows volcanologists to evaluate eruptions that may not have been well-monitored or were only observed by non-scientists. The scale is logarithmic with respect to eruption volume; this means that a VEI 5 eruption (the size of the 1991 Pinatubo eruption, for instance) is 10 times stronger than a VEI 4 eruption (the size of the 1980 Mount St. Helens eruption).

The VEI scale, however, is more a convenient way to describe the size of an eruption; it doesn't tell you much about the specific hazards at a volcano, because these are dependent on lots of other variables. A VEI 3 eruption at an Alaskan volcano like Redoubt is going to be a lot less hazardous than one at Mount Vesuvius, simply because Redoubt is located in such an isolated, unpopulated area and Vesuvius sits over a city of 3 million people.

(The image above is taken from the USGS Volcano Hazards Program Photo Glossary.)

Eruption forecasting in general is a tricky business. Even volcanoes that have been monitored for decades can behave in unexpected ways; if you look at things on a geologic timescale, those decades are only a blip in the volcano's history. The VEI is a great way to describe past eruptions, but the fact that a volcano has erupted with a certain magnitude doesn't necessarily mean it will do the same thing in the future.

Of course, you're all wondering what I would place my bets on. I certainly wouldn't rank Santa Maria along with Yellowstone; while the 1902 eruption was one of the largest in the 20th century, the only activity there now is at the Santiaguito lava dome complex, and it's a little hard to compare some little Vulcanian puffs with a potential caldera eruption. I'd probably have to go with Galeras, considering the activity that's been going on there lately, but don't take my word for it. (And tempting as it would be to fund some research by betting on an eruption, I wouldn't waste my money!)

Resources:

USGS Volcano Hazards Program Photo Glossary
Ready, Steady, Blow! Volcano Betting Erupts! (Paddy Power website)
Newhall, C. and Self, S., 1982, The Volcanic Explosivity Index (VEI): An Estimate of Explosive Magnitude for Historical Volcanism. Journal of Geophysical Research, v. 87, no. C2, p. 1231-1238.

Merry Christmas!

2009-12-25T12:44:00.002-05:00

And Happy Holidays too, because Christmas ain't the only holiday. (According to Straight No Chaser's "Christmas Can-Can", anyway!) Hope everyone is enjoying good food, friends and family, and staying safe - especially with all this crazy weather!

(This and a bunch of other cool backgrounds come from VladStudio. There are lots of Christmas ones, but this will always be my favorite!)

2 Year Blogiversary

2009-12-22T16:24:00.004-05:00

Two years already! (It's a good thing Callan started his blog up before I did, because otherwise I would completely forget to do this. Hope you're having fun in Patagonia, Callan!)

Things have changed quite a bit for me since I started this blog two years ago. I finished working at my first real job, started graduate school in a new state, got my first apartment, earned a great fellowship, visited active volcanoes in three countries, been invited to be on a GSA committee, started freelance writing, and adopted a new kitty. (Surprise! I thought I'd avoid putting a bunch of kitty photos up, but maybe just one or two at the end of the post...) It's been a very exciting time. Sometimes - in fact, often - stressful, sometimes crazy, but always interesting. (Isn't there some sort of curse to that effect? May you live in interesting times!)

The past year has been a big part of that. So far...

I earned an NSF Graduate Fellowship, and because it guarantees three years of funding, I'm almost finished switching from a masters to a PhD. This was something I certainly hadn't expected, but I'm happy with it, since after my first semester of grad school was over I knew I didn't want to stop work with a masters. It's just so fun! And I have great teachers at Buffalo - I've learned so much in the past year, and I'm really lucky to have found such a good fit in my graduate school. (And hey, I can't help but be excited about the fellowship, since it takes a lot of stress away. TAing and taking classes and trying to research all at the same time was rough.)
I went to Guatemala and Italy, and got to see volcanoes erupting in both countries. Guatemala was a real eye-opener for me - not just because Santiaguito is a really cool (and unique) volcanic dome, but because I'd never visited a third-world country before. Aside from the food poisoning, it was a fascinating experience, and it really drove home that I want to study volcanoes so I can help people as well as for the sake of research. I also felt my first big earthquake there! Italy was amazing, naturally, and I don't think I'll ever find another place that combines history, food and volcanoes in such a fun way. I hit a few rough patches on that trip too, but I'm glad I had the experience.
I gave my first talk at a professional conference. This was, frankly, petrifying, at least before I gave the thing. First talk of the session, 8 in the morning, in front of a whole room full of geologists who'd been working in my field area for decades? Talk about nerve-wracking! But the talk went well, I didn't run over my time, I managed to answer questions without sounding like an idiot, and no one got angry or argumentative when I gave conclusions that differed with their older studies. I know this won't always be the case, but at least I had a chance to ease myself into giving talks in a professional setting without being totally traumatized.
My volcano articles on Geology.com started getting pretty popular! In fact, one of the professors at UB who assigned an extra credit paper about volcanoes said that my articles were the second most popular reference in her 300-person intro class. She even congratulated me on it, which was neat. I'm glad that they're proving useful (and that people think they make good references for geology students). And I'm getting a lot of good writing practice in at the same time...

As I said, some big changes and great experiences. Hopefully there are a lot more to come! And now, because I promised, here's Sabrina, the newest member of my family, busily absorbing volcanology along with me:

Well, maybe not absorbing. But the Encyclopedia of Volcanology seems to make a good blanket, too!

Talk about a white Christmas!

2009-12-20T18:10:00.001-05:00

So in case you hadn't heard, the East Coast got hit with a lot of snow yesterday. I managed to get back to Virginia from Buffalo pretty early on Friday, so luckily I didn't get stuck in the mess. But I can't ever remember seeing this much snow in the DC area before! And especially not all at once...it was pretty crazy to be shoveling the driveway and have an inch of snow fall to cover what I'd just shoveled in less than 15 minutes.

Here's what it looked like at noon on Saturday:

Well, there used to be something growing in those planters...

It was pretty neat how much snow piled up on the fences.

Here's what our street looked like this afternoon. We actually got plowed pretty early on, but we haven't seen much traffic lately. Everyone's pretty much staying home, which is a good idea anyway.

I had to climb over our fence to get into the backyard, since our back porch is snowed in and the gate wouldn't open. I landed in snow to my knees.

Of course, I had to make a snow angel. I plan to make a snow volcano tomorrow.

Not quite deep enough for tunneling!

Crazy weather. (And I just found out that they closed all the schools in the county for the rest of the week. My mom is pretty surprised, but at least she gets a long winter vacation!) And since the DC area doesn't deal with snow well, I'm guessing we won't have really dug out until after Christmas.

And then they major in geology

2009-12-15T09:25:00.001-05:00

From Saturday Morning Breakfast Cereal:

http://zs1.smbc-comics.com/comics/20091215.gif

A year of traveling...and not traveling

2009-12-12T16:47:00.000-05:00

I saw this over at Sciencewomen, and I thought it would be a good way to recap what I've done this year.

January: NOVA & Washington D.C.

February: Stayed in Buffalo...

March: Guatemala!!

April: Florida

May: Utah, Toronto

June: Italy, Utah again

July: More Utah!

August: More Virginia

September: Niagara Falls

October: Portland

November: Ellicottville & Little Rock City, NY

December: Almost home again...

Old books and allergies

2009-12-01T22:32:00.000-05:00

Alas! Coursework strikes again, in the form of a rather intensive thesis proposal rewriting process, numerous projects on advanced topics in volcanology, and exams pretty much every week since September. (Perhaps an indication that I should quit taking classes for a bit, no matter how interesting I find them...) I feel bad for not posting much in the past couple of weeks, but blogging has to come after school obligations.

This topic popped into my head after I got fed up with my messy apartment and went on a cleaning and organizing spree, during which I probably shifted a few tens of pounds of books back to their shelves. A lot of my books are textbooks I've used in classes, or popular-science type volcanology books, but I've also got a small collection of older books about geology. One thing that I love to do is browse through the older journals and textbooks in the geology section of our library, and collect older texts that I find at book sales or used book shops. These are probably bad habits on my part, since I'm quite allergic to some sort of book mold, and I inevitably end up with itchy eyes and a nasty headache afterward.

But I can't quit! It's really fascinating to me to pick up an introductory geology text from, say, the pre-Wegener era, and see the old explanations for tectonic processes, or go even further back and find a 19th-century description of a field area that's as much a travelogue as a geologic history. Old maps are just as cool; one thing that I need to do sometime this winter is make my way down to the Buffalo central library and go see their copy of the William Smith 1815 geologic map of Great Britain.

My favorite discovery, though, was in the geology library at my alma mater. I was trying to see what the oldest book in our collection was, and came across a 19th century intro geology text. There were a lot of scribbled notes in the margins - and by scribbled I mean "more elegant cursive than I will ever achieve" - but one of them wasn't about geology. It read something like, "February 24, 1842...Rained all day."

This just cracked me up. Although it's not terribly likely that the book was ever used by a geologist at William & Mary back in the 19th century, that is just the sort of comment that I'd expect a bored student to write in the margins if they were sitting around Williamsburg in February, where it does, quite often, rain all day. Some long-dead student got bored with reading, just like I do sometimes...It was a neat way to connect with the past, and I'm always on the lookout for "new" old things, even if they make me sneeze.

Flatirons ≠ pyramids, but they're still cool

2009-11-25T13:19:00.002-05:00

I've noticed a few stories recently about Sam Osmanagich, a Bosnian archaeology enthusiast who claims to have discovered several 12,000-year-old 'pyramids' in the Balkans. The whole 'pyramid' saga mainly concerns a case of mistaken identity - the pyramids are just hills - and Indiana-Jones-style archaeology (by which I mean not very methodical, scientific or objective) on Osmanagich's part, and you can read more about it at the links below:

National Geographic: Pyramid in Bosnia - Huge Hoax or Colossal Find?
Smithsonian Magazine: The Mystery of Bosnia's Ancient Pyramids

They're really not hoaxes or mysteries, though - just badly misidentified. I minored in archaeology in college, and it really makes me cringe to see something so pseudo-scientific be accepted by so many people, even becoming a point of national pride in Bosnia. Archaeology has become a very scientific process, and properly-conducted archaeological digs are just as methodical as anything we do as geologists. Digging holes in a hillside, finding layered sandstones and conglomerates and then declaring that they're poured concrete mostly because they look like concrete is really crappy science. (There are also a lot of archaeologists who are unhappy about the whole situation because the 'pyramid' digs could potentially destroy a lot of genuine archaeological sites, which that area of the Balkans apparently has in abundance.)

Anyway, the situation is a great big mess. But what I found really interesting in the Smithsonian article was the (much more plausible) geologic explanation for the pyramids. Here's what the article says:

Visoko lies near the southern end of a valley that runs from Sarajevo to Zenica. The valley has been quarried for centuries and its geological history is well understood. It was formed some ten million years ago as the mountains of Central Bosnia were pushing skyward and was soon flooded, forming a lake 40 miles long. As the mountains continued to rise over the next few million years, sediments washed into the lake and settled on the bottom in layers. If you dig in the valley today, you can expect to find alternating layers of various thickness, from gossamer-thin clay sediments (deposited in quiet times) to plates of sandstones or thick layers of conglomerates (sedimentary rocks deposited when raging rivers dumped heavy debris into the lake). Subsequent tectonic activity buckled sections of lakebed, creating angular hills, and shattered rock layers, leaving fractured plates of sandstone and chunky blocks of conglomerate.

In early 2006 Osmanagich asked a team of geologists from the nearby University of Tuzla to analyze core samples at Visocica. They found that his pyramid was composed of the same matter as other mountains in the area: alternating layers of conglomerate, clay and sandstone.
Nonetheless, Osmanagich put scores of laborers to work digging on the hills. It was just as the geologists had predicted: the excavations revealed layers of fractured conglomerate at Visocica, while those at Pljesevica uncovered cracked sandstone plates separated by layers of silt and clay. "What he's found isn't even unusual or spectacular from the geological point of view," says geologist Robert Schoch of Boston University, who spent ten days at Visoko that summer. "It's completely straightforward and mundane."

"The landform [Osmanagich] is calling a pyramid is actually quite common," agrees Paul Heinrich, an archaeological geologist at Louisiana State University. "They're called ‘flatirons' in the United States and you see a lot of them out West." He adds that there are "hundreds around the world," including the "Russian Twin Pyramids" in Vladivostok. [From pages 2-3 of the article]

Well, if you're trying to draw attention to the fact that someone's mistaking a geological formation for a man-made structure, I guess saying it isn't "unusual or spectacular from the geological point of view" is a good way to do it. But I think that flatirons are still pretty neat, even if they're made out of conglomerate, which as a volcanologist I will have to admit is not on my 'most exciting rock' list.

I've seen a few good examples of flatirons in my time out West, and I'm always impressed by the forces it took to move all that rock around. Here are some novaculite flatirons from the Big Bend, Texas region:

A great Michael Collier photo of the flatirons at Waterpocket Fold in Utah, which is part of Capitol Reef National Park:

(Michael Collier is an amazing photographer and a great person; I was lucky enough to meet him while I was working at AGI. I dare you not to buy a book of his photos once you've seen a few.)

And probably the most famous US flatirons, the Flatiron range just outside of Boulder, Colorado:

From Wikipedia

It's not hard to see how one of these things could get covered over with soil and vegetation and look like it was man-made. But pure observation that isn't backed up by data will give you bad results every time, and flat, triangular rock formations do not a pyramid make. It's really too bad that so many people in Bosnia are getting excited about their flatirons because they think they're remnants of an ancient civilization, and not because they're a neat geological formation that tells us about the landscape evolution of that part of the Balkans. But we can't all be geologists, I guess...