Friday, December 25, 2009
Merry Christmas!
Tuesday, December 22, 2009
2 Year Blogiversary
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...
Well, maybe not absorbing. But the Encyclopedia of Volcanology seems to make a good blanket, too!
Sunday, December 20, 2009
Talk about a white Christmas!
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!
Tuesday, December 15, 2009
Saturday, December 12, 2009
A year of traveling...and not traveling
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...
Tuesday, December 1, 2009
Old books and allergies
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.
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.
Wednesday, November 25, 2009
Flatirons ≠ pyramids, but they're still cool
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:
Copyright (C) Michael Collier; hosted on the AGI Earth Science World Image Bank
(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...
Sunday, November 15, 2009
Little Rock City
Long time, no writing! I hate dropping the ball, but schoolwork has to come first. Anyway, I spent part of this weekend exploring the geology of Western New York - specifically, south of Buffalo in Cattaraugus County.
Cattaraugus County moves away from the carbonate sequences that you see around Buffalo and into Late Devonian sandstones and shales. On the map to the left, they're shown in a sort of pistachio green, while the limestones that I live on are in dark green. (You can find a copy of this map on the UB Library's map collection website - the resolution isn't great, but it's a pretty general map to begin with.)
The weekend was a combination geology and beer-and-wine-tasting trip, but Saturday was a lovely day for hiking, so we went for a visit to Rock City State Forest (roughly near the red arrow on the map). Cattaraugus County has a number of "rock cities" - places where the Salamanca conglomerate caps hills and breaks up into large blocks along joints. According to a K/H Geology Field Guide series book on Upstate New York, "where the rock cites occur, a conglomerate ledge forms a level, ribbon-like outcrop that follows the contour of the hill for a way and then seems to just fade out."
The rock cities are really fun, and look to be prime bouldering locations; the cracks between the blocks are anywhere from inches to feet wide, so there are lots of alleys and cracks to explore.
I'd recommend a visit to anyone who's in the WNY area; this is a small but probably underappreciated park that many people would probably overlook in favor of the larger parks (or the ski areas, which I'm sure are lovely when they have some snow...)
Cattaraugus County moves away from the carbonate sequences that you see around Buffalo and into Late Devonian sandstones and shales. On the map to the left, they're shown in a sort of pistachio green, while the limestones that I live on are in dark green. (You can find a copy of this map on the UB Library's map collection website - the resolution isn't great, but it's a pretty general map to begin with.)
The weekend was a combination geology and beer-and-wine-tasting trip, but Saturday was a lovely day for hiking, so we went for a visit to Rock City State Forest (roughly near the red arrow on the map). Cattaraugus County has a number of "rock cities" - places where the Salamanca conglomerate caps hills and breaks up into large blocks along joints. According to a K/H Geology Field Guide series book on Upstate New York, "where the rock cites occur, a conglomerate ledge forms a level, ribbon-like outcrop that follows the contour of the hill for a way and then seems to just fade out."
The rock cities are really fun, and look to be prime bouldering locations; the cracks between the blocks are anywhere from inches to feet wide, so there are lots of alleys and cracks to explore.
The conglomerate is really cool; it has some beautiful cross-bedding, normal and reverse grading sequences, and imbrication in the flat pebbles that make up the largest clasts. The pebbles are mostly white quartz or quartzite, but every so often there are little bits of shale.
I'm too out of practice to be bouldering without a spotter and the right shoes, but the crack climbing was just fine for some of the folks on the trip...
The conglomerate retains water very well - I guess you could consider the blocks "perched aquifers". There are little dripping springs all over the sides of the blocks, and the water tends to pool at the bases. It makes for muddy hiking, but somebody went to the trouble of putting down wooden walkways in some spots.
Luckily, it was a nice day for hiking; it's all too easy to get so caught up in the research part of geology that you forget to go out into the field. (The crazy weather up here right now also helped; we should probably be getting snow at this point, but it was warm enough yesterday to go outside in short sleeves! I'm betting this means we're going to get dumped on this winter.)
I'd recommend a visit to anyone who's in the WNY area; this is a small but probably underappreciated park that many people would probably overlook in favor of the larger parks (or the ski areas, which I'm sure are lovely when they have some snow...)
Saturday, October 31, 2009
Accretionary Wedge #21: Earth Science Outreach
That's why the subject of this month's Accretionary Wedge was Earth Science Outreach. This October has been a big month for Earth science: we've had Earth Science Week (a yearly event), a national Geological Society of America meeting in Portland, OR, and a DonorsChoose challenge on ScienceBlogs (Geobloggers Giving Kids the Earth), sponsored by geobloggers Kim Hannula, Anne Jefferson, and Erik Klemetti.
But individual Earth scientists do just as much to show others why our work is important. Read on to find out what!
Earth science outreach happens outside of a school setting as well, whether it's through a visit to a museum, field trips, short courses, or teaching others to teach geoscience. Pascal of Research at a snail's pace spent time trying to make the University of Wisconsin Geology Museum - and specifically its Burgess Shale exhibit - a little easier to visualize. (A good thing, since most of them were so hard to figure out that they got stuck in a genus called Hallucigenia!) Over at Geology Happens, we get to hear about opportunities for K-12 teachers and students to explore the Colorado Plateau
Finally, it's important to remember that Earth science outreach isn't just about showing people how wonderful the geosciences are - it's about providing opportunities to those who wouldn't necessarily have them. There are schools all over this country (and others) where teachers are incredibly dedicated to their students' education, but just don't have the means to teach them about science. Good tools aren't cheap, as anyone who's ever swung a rock hammer will know. That's why the ScienceBlogs Donors Choose Challenge was such a hot topic this month. Kim Hannula of All of My Faults Are Stress Related was part of the team who sponsored a challenge for geobloggers and their readers, with the goal of funding geoscience-related projects for classrooms in need. And it was a resounding success! Kim's post says it all: "October's over tomorrow, and the geobloggers' challenge has raised more money than any other challenge here at Science Blogs. $8,288. 40 donors. 1218 students reached. Last week, I had to go searching for new geoscience-related projects to support, because so many of the original projects had already been completely funded." Bravo, geobloggers! And remember, just because the ScienceBlogs Challenge is over doesn't mean the projects still don't need funding - go check out the geobloggers page and see who still needs help!
Thanks for everyone who contributed to this month's Accretionary Wedge - and thank you again for all the Earth science outreach you do, no matter how you do it! (Even through blogging...) As always, if you've got a late contribution or I've missed anything, leave a link and I'll add you on.
There's still no one hosting the Wedge for November, so if you have an idea, leave a comment at Who's hosting the next Accretionary Wedge? (and step up and volunteer some more, if you feel like it!)
Labels:
accretionary wedge,
Earth Science Week,
field trips,
outreach
Friday, October 30, 2009
Last call for Accretionary Wedge entries....
Monday, October 26, 2009
The "Breached Dam Overlook" Field Trip at GSA: perspectives from a participant
Part 1
Part 2
Part 3
Part 4
Part 5
And now, for those of you who wanted to see how the field trip actually turned out, on to the trip summary:
To finish up, here are a few thoughts from Pascal's last post about why using social networking for the sake of science can be really beneficial:Introduction
"First, let me talk about what this post is not:
It is not a discussion of Dr. Steven Austin's character as a person. In fact, I found him to be very cheerful and enthusiastic despite the poor weather. The same could be said of all the people on the trip; people were generally quite upbeat and positive even if our boots still have not dried out completely.
"It is not a discussion/rant about religion - I find the parts of religious teachings that say we should be nicer to each other rather spiffy. There are plenty of other places to attempt some kind of cost/benefit analysis of belief/non-belief in any particular deity.
"My intention with this post is to describe the trip in terms of how it was laid out, where we went, what we saw, and what was said by the trip leaders as it pertained to the field trip. I will save posts related to implications of the trip and discussion of some of the abstracts submitted by other authors who were on the trip for the future."The Trip
"We boarded the bus at the convention center and started up I-5 towards MSH. Along the way, Steven described the general purpose for the trip and handed out a reprint of the Guidebook [published as part of the GSA meeting field trip guidebook - more on this later]. It appeared that at least half of the people on the trip were familiar with the leader or co-leaders [I am still not sure how many actual "co-leaders" there were - at least four]. One of my friends from grad school was also on the trip, but I did not know any one else aside from the background research I had done to familiarize myself with the writings of those involved in planning the trip.
"While we were making our way north, Steven described scuba diving in Spirit Lake, some of the work he had done for his dissertation at Penn State, and mentioned several times how the people attending this trip could learn from it and lead their own tours in the future. He described the eruption as a seven or eight step sequence of events from initial quake and landslide, to steam explosion and ashfall, finally ending with the breach of the new spirit lake and rapid outlet of the Toutle River once it overtopped the debris damming the valley two years later. A great deal of emphasis was put on the time of each event and the quantity of material removed from the mountain and depth of erosion from the Toutle River. Oddly, he described the basal movement of the mountain side as "laminar flow."
"He spent some time describing "long-runout landslides" and the various mechanisms by which they can travel [there was nothing that seemed obviously wrong with his summary of primary concepts - although I have not double checked his reference yet]. He also spent some time describing hyperconcentrated mudflows along the Cowlitz River, which he described as turbulent, making bedforms. Traditional mudflows, he stated, had laminar flow and left massive, lacking bedforms/structures [which was confusing, since turbulence is largely a function of flow thickness, velocity, and bed interference, and even laminar flow can form sedimentary structures].
"He made some comment about these landforms being a result of "self-organized criticality," but I'm still not sure to what he was exactly referring [the eruption, the landslide, the breaching of the dammed material?] We got out at JRO to spend some time in the center to look at the displays and look at the [really cool] topographic model of the area with fiber optic lights to show the extent and pattern of eruptive events on the mountain. [I should really talk about JRO and MSH itself in a separate post].
"The group was split into groups of four [to help ease congestion on the trail and stops]. We then proceeded to wind our way down Truman Trail and into the valley. That's when it started to rain. Not a sprinkle or even a simple cloudburst, but sideways and nonstop for about four hours. This driving rain forced the trip leaders to postpone the first stop (on the ridge) to the return trip, so we continued on our trip. Down into the debris field, with Spirit Lake visible to the East, and the base of MSH occasionally visible. However, we didn't have much opportunity to gaze at the vista, since it was raining so hard [very few photos, either, since I wanted to keep my lenses dry for a while].
"We continued down the trail, eventually reaching the bottom of the valley, where we veered off the trail and toward the new channel canyon. Steven had obtained an off-trail permit for our group, and we plodded through the rain-soaked clay, ash, and volcanic rock debris towards the overlook. I kept my hood over my face to try and keep the rain from draining down the inside of my jacket. By this time my pants, boots, and socks had become completely saturated. Because I was moving, I wasn't feeling cold, however, and the rest of the group also appeared to take the weather in stride.
"Our arrival at the "breached-dam overlook" allowed us to see some of the more prominent erosional features of the Toutle River Valley. Here Steven picked up his narration, describing the landforms as a result of specific processes that had occurred at specific "moments" in time [my wording].
"After his description of the various landforms [basically: 1) debris hummocks, 2) ash-fall, and 3) erosional valleys], Steven mentioned again, that this landscape was a result of "self-organized criticality" [his wording]. There were some questions and comments from the attendees regarding past volcanic events and landscape processes, even a statement about something that happened "100 million years ago" to which Steven did not react or criticize. But then he left us with some oddly phrased question about how much of this landscape was a result of "catastrophic" change versus "gradual" change. To which another person [I do not know if they were co-leading or attending] added that "both types have occurred. I was still trying to parse his catastrophism comments, so I only asked one question about this particular landscape in the future: "what would you expect to see in this landscape in the distant future?" I don't think he quite understood what I was asking, but he did address the fact that this particular landscape was anthropogenically altered, therefore some changes would not take place [which was entirely correct]. But as a summary, his statement was "more erosion." Nothing about changes in stream power, or sediment load, or base-level fluctuations. Just "erosion."
"Because of the rain, his stop was likely cut short. As a parting comment about future eruptions, he made some comment about a similar 1980-style event unlikely [I'm not sure if he was talking about never again, or just in the relatively short-term]. But he made some passing comment about eruptions occurring as a result of the interaction between water, crystallization of magmas [my impression was he thought crystallization was near-instantaneous], and "self-organized criticality" allowing for this pressure to be released [his wording again]. I didn't have a chance to follow-up on that and ask him what he meant, since everyone had started to hike back to the ridge [I still need to do that].
"When we got up towards the ridge, the rain let up and I concentrated on taking photographs. Most of the group had started to spread out, such that I only saw the same four or five people at any given time. Arriving back at JRO, the overlook stop had apparently been cancelled, so I stood on the observation deck and took lots and lots of pictures.
"The return trip to the Convention Center was unremarkable, except that when we got off the bus, they handed a nice 60" wide panoramic photo of MSH to each of the attendees [this was pretty cool]."So...
"Ultimately, the trip was not as embarrassing or intellectually painful as I had feared. If a GSA member had signed up for the trip, they may not have realized that the trip leader was a YEC [my grad school friend didn't know about Steve Austin until I mentioned something on the bus when we left for MSH]. The people sympathetic to his views were obviously happy. I took away some nice photos and memories of the volcano itself along with a clearer picture of what these YEC-ers are up to and what they are thinking.
"I want to thank Steven Austin and his colleagues for taking the time and effort to organize the trip. I have some concerns, but these are more appropriate for a letter to the GSA Field Trip Committee Chairperson.
"I also want to commend GSA for their decision. It wasn't a tough one, and understandably, there was a great deal of internal discussion related to the trip and whether to allow it. As written, the description of the trip makes no statements regarding a "Young Earth" or other sentiments anathema to the GSA mission. In addition, to deny a proposal on the "possibility" of something coming up is a big step down the slippery slope of guilt by association.
"Yes, the YEC crowd will put this as a shining feather in their caps [ironic, since they claim all of our work is wrong yet they view interaction with us as "proof" that their ideas have merit]. But, there are always unintended consequences. Thanks to the hard work of Jessica at Magma Cum Laude, I was aware of the situation prior to the event, and I've been able to share my experiences with sufficient prior knowledge to report on the event. I also have gained valuable insight into the YEC community, and a new lesson plan to teach about deep time - using Austin's work to show why it's completely wrong."
"This brings up an important point about social networks. The conference at GSA held a special session on the use of social networks in teaching and research. I think the use of social networking tools such as blogs, tweets, and facebooks is vital to help make the geologic community aware of what's going on. Without it, I would not have been able to be aware of the nature of the field trip: both in its implications, but also in terms of its "science" content. In addition, I might not have pursued the background research and stumbled upon these abstracts. The activities of the young-Earth community clearly are part of a larger strategy to gain "scientific merit" for their views (this is related to the "Wedge" strategy as described by the Institute for Creation Research). Without social networking, this behavior might not have been discovered until later - at a point where response and criticism would be more complicated.
"As geologists, we ignore people like Steve Austin, John Witmore, and Timothy Clarey at our peril. However, our response must be both thorough and united. Social networking can provide the first line of notification. I want to thank Jessica at "Magma Cum Laude" for her first note: without it, I - and others - would have been duped."
Saturday, October 24, 2009
GSA Update #3
Tuesday at GSA was another great chance to see talks; lots of discussion about volcano hydrothermal systems, degassing, hazards, and risk communication. In addition, I (and Jim Lehane from Dino Jim's Musings) were asked to be on a the eGSA ad hoc committee! We had a really interesting discussion about how GSA communicates with its members online, and ways that we can incorporate new technology to help GSA keep up with current online trends (such as geoblogging). Some exciting topics came up, including the possibility of a GSA blog, an improved GSA Connection newsletter and maybe even a meeting-oriented Iphone app.
Anyway, on to a few talk summaries:
- Conduit convection vs. deep degassing at open vent volcanoes: melt inclusion evidence from Popocatepetl Volcano, Mexico by Paul Wallace. In this study, melt inclusions were found to indicate variable degassing at different depths in a volcanic system; CO2/SO2 ratios of volatiles dissolved in the inclusions were used to determine the pressure and depth of exsolution. The CO2/SO2 relationship is something that I was taught about in a volcanology field course I took in Hawaii; CO2 degassing occurs at depth and SO2 degassing when the magma reaches a more shallow location, and increasing amounts of SO2 are often taken to indicate a likely eruption (or at least magma moving into a shallow part of a volcanic conduit).
- Back off: We're scientists! Myth vs. reality and how to communicate risk related to natural hazards by Jeff Rubin. Jeff was one of the teachers of the short course I took on Sunday, and this talk was a great summary of the important points that came up during the discussions he led. One of the biggest problems with mitigating natural hazards is the assumptions that people in charge make about how non-scientists and non-officials will behave - especially thinking that they will panic. In reality, panic is extremely rare and in many cases precious resources and personnel are wasted on trying to prevent it. What folks in charge should be concentrating on is communicating clearly and honestly about hazards, and maintaining credibility (by not withholding information unnecessarily, or refusing to admit a lack of certainty, for example).
- The preacher vs. the volcanologist: Origin of the word "pyroduct" by Jack Lockwood. This was one of the history of geology talks, and it was a great tale about Reverend Titus Coan, who went to Hawaii in the 1850s to help spread Christianity to the natives and in the process made some important observations about volcanoes, and the more famous James Dana (of Dana's Mineralogy), with whom he corresponded. Coan's letters to Dana about eruptions at Mauna Loa were the earliest field descriptions of activity at that volcano, and they caused a long-standing argument between the two about the existence of lava tubes. In short, Coan described them and Dana (who had not been to the field and actually looked at them) republished his work but denied that lava tubes (or "pyroducts", as Coan called them) existed. (Only after Coan's death did Dana even partially relent, in fact.) Dr. Lockwood left us with a moral to the story: Good field observations trump office speculations every time!
- Blogs as a resource and social support network for women geoscientists by Kim Hannula (of All of My Faults Are Stress Related). I was really looking forward to this talk, because it presented the results of one of the surveys that's been bouncing around the geoblogosphere in the past months. The point of the survey was to find out why women read (and write) geoblogs, and the results were pretty interesting: women geoscientists in academia read and write blogs to make their experiences feel more normal, and to get advice and connect with role models. This wasn't so much the case for geoscientists in industry, and Kim has promised some further research on why the responses were different. You can read her summary here - as one of the PIs of the study, she's better at summarizing it than I am!
And on Wednesday, I rested....just kidding. On Wednesday, noticing a lack of volcanology-related sessions, I decided to tromp around Portland for a bit. Sadly, it was a pretty soggy morning, and most stores didn't open until 10 (which probably kept me from spending money on things I'd have to stuff into my already-full bags), but I enjoyed the chance to see a bit of the city. I'll have to go back and visit some volcanoes, because I didn't see any in the whole time I was there. Darn!
All in all, a great meeting - it's not often that there are talks on volcanology every day, and I felt like I learned a lot and made some good connections. (And I couldn't beat the geobloggers meetup for a good time!)
Accretionary Wedge #21 - Deadline extended!
In recognition of the fact that I'm still "recovering" from GSA, and that quite a few geobloggers are probably doing the same thing, I'm going to extend the Accretionary Wedge deadline to Friday, October 30. (And yes, this does give me an excuse to throw some Halloween stuff in there...)
The original announcement can be found here - this month's theme is Earth Science outreach. I noticed that a few people had posts up about Earth Science Week activities and the DonorsChoose campaign - those are great topics for this month's Wedge!
Don't forget to submit your entries in the comments here or on the original announcement (or by emailing them to me through magmacumlaude AT gmail.com
The original announcement can be found here - this month's theme is Earth Science outreach. I noticed that a few people had posts up about Earth Science Week activities and the DonorsChoose campaign - those are great topics for this month's Wedge!
Don't forget to submit your entries in the comments here or on the original announcement (or by emailing them to me through magmacumlaude AT gmail.com
Tuesday, October 20, 2009
GSA Update #2
- Can static magma decompression trigger an eruption? Evidence from Kilauea Volcano, Hawai'i by Mike Poland. Many eruptions are associated with inflation of a volcanic edifice as magma moves into its "internal plumbing", but during the recent eruption at the Halema'uma'u crater at Kilauea's summit, decompression and deflation were observed. One hypothesis to explain this suggests that decompression in the magma chamber releases gases that can clear old channels for magma movement.
- Characteristics and models of cyclic activity at Fuego Volcano, Guatemala (2005-2007) derived from visual observations and seismic, acoustic and thermal measurements by John Lyons. Fuego is a basaltic Guatemalan volcano that experiences cycles of "flow" (lava flow with minor Strombolian), "chug" (violent Strombolian and lava fountaining) and "pop" (explosions without effusion) activity. The authors applied the collapsing magmatic "foam" model of Jaupart & Verniolle to explain these cycles: flow behavior represents constant effusion of small bubbles of gas with magma near the top of the conduit, chugging represents continuous release of large bubbles, and popping happens when bubbles are released but the magma free surface is some distance below the mouth of the summit conduit.
- Field trips as a tool for recruitment, retention and education by our own Callan Bentley of NOVA Geoblog. Callan often leads geology field trips along the Billy Goat Trail in the Great Falls area of Maryland, and finds that they're an important way of both stimulating the interest of his students and getting them excited about geology. I think my favorite quote was from one of the students he surveyed, who said that "Callan's field trips are like crack - I'm just here to get my fix." Having been on the Billy Goat Trail trip before, I totally agree.
- Challenges to volcanic risk mitigation by John Ewert. There are physical, technical and social challenges involved in volcanic risk mitigation (volcanic risk is a combination of the chance of volcanic hazards occurring combined with the possible monetary, human, etc. consequences). Many of them have to do with how complicated volcanic behavior is, how difficult it is to forecast, and the importance of continual, timely hazard education and communication. It's not an easy job - but it's definitely important!
Monday, October 19, 2009
Quick GSA Update
(I've been having the really cool experience of being recognized for my blogging by folks at the meeting. Me a minor celebrity? Wow!)
Hopefully more updates later today, unless I'm totally tired out by talks & receptions.
Friday, October 16, 2009
Bloggers galore at GSA
Sunday October 18:
IMPACTS OF BASALTIC VOLCANISM ON INCISED FLUVIAL SYSTEMS: DOES THE RIVER GIVE A DAM?
HOUSE, P. Kyle, BROSSY, Cooper C., SAFRAN, Elizabeth, ELY, Lisa L., and O'CONNOR, Jim
Session No. 6
The Evolution of Basaltic Landscapes: Time and the River and Lava Flowing
Oregon Convention Center: Portland Ballroom 254
8:00 AM-12:00 PM, Sunday, 18 October 2009
Presentation Time: 9:05 AM-9:35 AM
FROM DINOSAURS TO VOLCANOES: HELPING STUDENTS LEARN FROM HOLLYWOOD'S MISTAKES
LEHANE, Jim
Session No. 2
Geoscience Education I
Oregon Convention Center: C123
8:00 AM-12:00 PM, Sunday, 18 October 2009
Presentation Time: 9:20 AM-9:35 AM
USE OF THERMOPLASTIC SAND IN PHYSICAL MODELS OF FLUVIAL SYSTEMS
GOUGH, Steve C.
Session No. 2
Geoscience Education I
Oregon Convention Center: C123
8:00 AM-12:00 PM, Sunday, 18 October 2009
Presentation Time: 11:05 AM-11:20 AM
DIGITAL GEOLOGY IN THE 21st CENTURY: IT'S HERE, DON'T FEAR, GET INTO IT
HOUSE, P. Kyle
Session No. 53
Google Earth to Geoblogs: Digital Innovations in the Geosciences
Oregon Convention Center: Portland Ballrooms 251/258
1:30 PM-5:30 PM, Sunday, 18 October 2009
Presentation Time: 1:30 PM-1:45 PM
I TWEET, THEREFORE I AM: SOCIAL NETWORKS IN THE GEOSCIENCES
ALLISON, M. Lee
Session No. 53
Google Earth to Geoblogs: Digital Innovations in the Geosciences
Oregon Convention Center: Portland Ballrooms 251/258
1:30 PM-5:30 PM, Sunday, 18 October 2009
Presentation Time: 2:00 PM-2:15 PM
GigaGeology: VIRTUAL FIELD TRIPS IN A Web2.0 WORLD
SCHOTT, Ronald C.
Session No. 53
Google Earth to Geoblogs: Digital Innovations in the Geosciences
Oregon Convention Center: Portland Ballrooms 251/258
1:30 PM-5:30 PM, Sunday, 18 October 2009
Presentation Time: 2:30 PM-3:00 PM
CHANGES IN RHYOLITE COMPOSITION OVER THE LAST 60,000 YEARS AT THE OKATAINA CALDERA COMPLEX, NEW ZEALAND RECORDED IN ZIRCON TRACE ELEMENT ZONATION
KLEMETTI, Erik W.
Session No. 41
Supervolcanoes, Ignimbrite Flare-ups, and Their Impacts: Definition, Debate, and New Developments (Posters)
Oregon Convention Center: Hall A
9:00 AM-6:00 PM, Sunday, 18 October 2009
Presentation Time: 9:00 AM-6:00 PM
DOCUMENTING THE TIMESCALE OF PLUTON CONSTRUCTION: U-PB GEOCHRONOLOGY OF THE SUBVOLCANIC VINALHAVEN INTRUSION AND ASSOCIATED VOLCANIC ROCKS
HAWKINS, D.P., BROWN, N.E., WIEBE, R.A., KLEMETTI, E.W., and WOBUS, R.A.
Session No. 43--Booth# 400
Pluton Assembly: Duration, Mechanisms, and Structural Controls (Posters)
Oregon Convention Center: Hall A
9:00 AM-6:00 PM, Sunday, 18 October 2009
Monday October 19:
FIELD TRIPS AS A TOOL FOR RECRUITMENT, RETENTION, AND EDUCATION
BENTLEY, Callan
Session No. 90
Geoscience Programs at Community Colleges: Models for Success and Innovation
Oregon Convention Center: C124
8:00 AM-12:00 PM, Monday, 19 October 2009
Presentation Time: 10:30 AM-10:45 AM
Tuesday October 20:
IMPORTANCE OF PREDECESSOR BASIN HISTORY ON PROVENANCE OF THE MAGALLANES RETROARC FORELAND BASIN, CHILE (50°S-52°S)
ROMANS, Brian W., FILDANI, Andrea, GRAHAM, Stephan A., COVAULT, Jacob A., FOSDICK, Julie C.3, and HUBBARD, Stephen M.
Session No. 200
Tectonics and Basins of Convergent Margins
Oregon Convention Center: A107/108/109
1:30 PM-5:30 PM, Tuesday, 20 October 2009
Presentation Time: 3:35 PM-3:50 PM
BLOGS AS A RESOURCE AND SOCIAL SUPPORT NETWORK FOR WOMEN GEOSCIENTISTS
HANNULA, Kimberly A., JEFFERSON, Anne J., CAMPBELL, Patricia B., FRANKS, Suzanne E.
Session No. 210
Techniques and Tools for Effective Recruitment, Retention and Promotion of Women and Minorities in the Geosciences
Oregon Convention Center: B117/118/119
1:30 PM-5:30 PM, Tuesday, 20 October 2009
Presentation Time: 5:00 PM-5:15 PM
GROUNDWATER CONTRIBUTIONS TO HEADWATER STREAMS ON FRACTURED ROCK IN THE NORTH CAROLINA PIEDMONT AND BLUE RIDGE
JEFFERSON, Anne J., ABRAHAM, Joju, CAMPBELL, Ted R., and MOORE, Cameron
Session No. 177
Stream-Groundwater Interaction: New Understanding, Innovations, and Applications at Bedform, Reach, and River Network Scales (Posters)
Oregon Convention Center: Hall A
9:00 AM-6:00 PM, Tuesday, 20 October 2009
PROTOTYPING A GEOLOGY LAYER FOR GOOGLE EARTH
SCHOTT, Ronald C.
Session No. 192--Booth# 372
From Virtual Globes to Geoblogs: Digital Innovations in Geoscience Research, Education, and Outreach (Posters)
Oregon Convention Center: Hall A
9:00 AM-6:00 PM, Tuesday, 20 October 2009
Wednesday October 21:
SEDIMENT SIZE DISTRIBUTIONS IN FORESTED HEADWATER STREAMS OF THE NORTH CAROLINA PIEDMONT
MOORE, Cameron and JEFFERSON, Anne J.
Session No. 244--Booth# 65
Geomorphology (Posters)
Oregon Convention Center: Hall A
9:00 AM-6:00 PM, Wednesday, 21 October 2009
ANCIENT LANDSLIDES, LANDSLIDE DAMS, AND OUTBURST FLOOD POTENTIAL IN AN EXTENSIONAL SETTING
CROALL, Kelsey, JONES, Emily, SAFRAN, Elizabeth, O'CONNOR, Jim E., HOUSE, P. Kyle, and ELY, Lisa L.
Session No. 244--Booth# 76
Geomorphology (Posters)
Oregon Convention Center: Hall A
9:00 AM-6:00 PM, Wednesday, 21 October 2009
SHORTENING UNDER EXTENDED CIRCUMSTANCES: REGIONAL STRUCTURE OF THE CRETACEOUS-NEOGENE PATAGONIAN FOLD-THRUST BELT AND MAGALLANES BASIN, CHILE AND ARGENTINA (51°30' S)
FOSDICK, Julie C., ROMANS, Brian W., FILDANI, Andrea, CALDERÓN, Mauricio N., BERNHARDT, Anne, and GRAHAM, Stephan A.
Session No. 253
Tectonics and Basins of Convergent Margins (Posters)
Oregon Convention Center: Hall A
9:00 AM-6:00 PM, Wednesday, 21 October 2009
I get on a plane tomorrow, and I'm really looking forward to the meeting. I probably won't be able to live-blog everything, but I'll do my best to write summaries of my days in the evenings. See you all in Portland!
Sunday, October 11, 2009
Catching up
- Earth Science Week is this week! I've got my toolkit, although lack of free time mostly means that I'll be putting up posters instead of sponsoring an event. Still, there are lots of things going on - check out the ESW Events Near You page and see what's happening in your state.
- GSW Portland starts on Sunday (Saturday if you go to the welcome dinner). Callan has posted details for a geobloggers meetup at the Tugboat Brewing Company in downtown Portland (8 PM on Monday night). I'll be there - hope to see some of the rest of you!
- GSA has an ad hoc committee on electronic communication (eGSA), and one of the members wants to put my name forward to be on it! I'm still awaiting details, but it looks like I may be in a position to make suggestions for how GSA can better utilize current web technology for communication. More details to come...
- Don't forget the next Accretionary Wedge! The suggested due date for entries is the Sunday after GSA (Oct. 25th), but of course I'll add more entries as they come in. The theme this time around is Earth science outreach, so dust off those old field trip and demo photos and share some knowledge!
- The deadline for the NSF's Graduate Research Fellowship Program is coming up fast - November 5th for the geosciences. If anyone out there is getting an application together and would like to talk to a real live Fellow (as I was introduced at an information session not too long ago), I'd be happy to answer questions about the application or the program.
Labels:
accretionary wedge,
conferences,
Earth Science Week,
funding
Friday, October 2, 2009
Looking for something to do for Earth Science Week?
This is a great way to make sure that Earth science outreach and learning happen in schools that are struggling to make ends meet. I'm definitely going to donate what I can, and I hope that all of you will think about doing the same!
Friday, September 25, 2009
Accretionary Wedge #21: Call for posts
Which brings us to the next topic of interest: October's Accretionary Wedge (#21), which will be hosted here. October is a big month for Earth science this year - not only is the Annual National GSA meeting happening in Portland from October 18-22, but it's also the month of Earth Science Week (October 11-17). In other words, it's a month for sharing knowledge about the Earth (something that we geobloggers do a lot).
What kind of Earth Science outreach have you participated in? Have you hosted a geology day at your department, given a field trip, gone to your child's/niece's/nephew's/cousin's school to do a demonstration, or sponsored an event for Earth Science Week? (This year's Earth Science Week is about Understanding Climate, so if you're a climate scientist, please chime in!) What was your favorite experience (or what funny stories came out of one that didn't go as planned)?Since GSA is going to take up a big chunk of peoples' time, I'll set the due date for the weekend after the Portland meeting (Sunday, October 25th). If you're doing something for GSA or Earth Science Week, you should have plenty of time to write about it for the Accretionary Wedge - plus this edition of the Wedge gives you good incentive to plan something if you haven't already. (And, as always, if you're a little behind on your blogging, late entries will be added as they're received.)
Leave a link to your post in a comment or send it to me by email at magmacumlaude AT blogspot.com (replacing "AT" with @). Happy writing!
Sunday, September 20, 2009
Accretionary Wedge #20: Geologic discoveries for the future
David Bressan at cryology and co. posed this question for the latest edition of the Accretionary Wedge:
What remains to be discovered for future earth scientists what we (still) don't know about earth? What are the geological riddles that still lack answers - all questions are allowed - it could be a local anomaly, or a global phenomena, or something strange...(Naturally you can also include a possible answer to your problem).
One question I'd like to see answered in the future is something that many volcanologists have been (and are still) trying to figure out: What does the inside of a volcano really look like?
Early scientists thought that volcanoes were the homes of gods, or passages to Hell, or conduits for a vast network of subterranean fires. (At left is Athanasius Kirchner's 1664 engraving of the interior of Mount Vesuvius, from his book Mundus Subterraneus. Image from Art.com.) These ideas have all fallen by the wayside, but volcanologists today are still trying to work out the details of volcano 'plumbing', as it's commonly called.
This is no easy task. For one thing, there are many different kinds of volcano; it stands to reason that they're not going to have similar plumbing systems or structures. For another, if you're interested in what's going on inside an active volcano, it's understandably a little difficult to get close enough to the object in question to even begin to work on the question.
So how do volcanologists know anything at all about the interior of volcanoes - and how can they find out more?
One of the easiest ways is to look for volcanoes that are no longer active, and have been worn down by time and erosive forces. There are actually some great examples of these: The Summer Coon volcano in southern Colorado, which shows a spectacular radial pattern of dikes (see the Google Earth image at right); the cinder cones in the Southwestern Nevada Volcanic Field, which one of my professors studies (Keating et al., 2008); even my own study area, at the Santa Maria volcano in Guatemala, has a spectacular view of the internal structure of a stratovolcano (revealed by the 1902 eruption that blew a huge crater in the side of the mountain).
Another way is to use geophysical or remote sensing methods. Volcano seismology (including 3D seismic tomography, sort of a CAT-scan for volcanoes) has been used for years to locate and define the shapes of magma chambers under volcanoes, as well as the dikes and conduits which feed eruptions. For smaller edifices, methods such as ground-penetrating radar can give some idea of the shallow structure. Some researchers in Japan (Miyamachi et al., 1987) have even used explosions from fireworks to image the interior of lava domes (using the shock of the fireworks explosions to take the place of seismic shocks). GPS, ground tilt, and other deformation measurements give volcanologists an idea of how a volcano changes shape and volume, and from that some idea of the internal workings of the volcano can be discerned.
One interesting study by researchers in Japan (Sakuma et al., 2008) details a project where volcanologists actually drilled into an active volcano - Mount Unzen, which last erupted in 1996 and produced a summit lava dome. The Japanese volcanologists found a conduit with several feeder dikes, showing that Unzen's eruption wasn't fed by a single tube but several, and possibly from many sources. Still, this is only a small part of the volcano, and it's a very expensive and tricky way of finding things out.
Because of these methods, we know something about the interior of volcanoes. For example, the old chamber-conduit-summit eruption model for stratovolcanoes is, we now know, an extremely simplistic and not entirely correct view; many stratovolcanoes are riddled with dikes and smaller pockets of magma and other interesting things like cryptodomes. And they're hardly ever as nicely layered as this image suggests. (From the USGS Eastern Geographic Science Center Volcanoes! teacher resource.)
But we've still got a long way to go. You can't just X-ray a volcano, and it's very difficult to image an entire mountain with other methods, especially if it's in a remote area, large, and (as they tend to do), erupting. Knowing the plumbing of a volcano is, however, important for forecasting how the volcano will behave: Will it erupt vertically or laterally? Is the magma chamber shallow or deep, large or small, and is there more than one? Could there be outbreaks of lava on the flanks as well as the summit? Is the volcano structurally stable or collapsing? Does it contain a pressurized cryptodome that could explode, or lava that will ooze out of vents? These are all questions that depend on what we can find out about a volcano's insides, and that's something that volcanologists are always working on.
And hey, maybe I'm being pessimistic and someone will invent a whole-body-scan for a volcano. It could happen...
Additional reading:
Keating, G.N. et al., 2008, Shallow plumbing systems for small-volume basaltic volcanoes. Bulletin of Volcanology, v. 70, p. 563-582.
Miyamachi, H. et al., 1987, Seismic experiments on Showa-Shinzan lava dome using firework shots. Pure and Applied Geophysics, v. 125, no. 6, p. 1025-1037.
Poland, M.P. et al., 2004, Patterns of magma flow in segmented silicic dikes at Summer Coon Voclano,Colorado; AMS and thin section analysis. Earth and Planetary Science Letters, v. 219, p. 155-169.
Sakuma, S. et al., 2008, Drilling and logging results of USDP-4; penetration into the volcanic conduit of Unzenvolcano, Japan. Journal of Volcanology and Geothermal Research, v. 175, p. 1-12.
What remains to be discovered for future earth scientists what we (still) don't know about earth? What are the geological riddles that still lack answers - all questions are allowed - it could be a local anomaly, or a global phenomena, or something strange...(Naturally you can also include a possible answer to your problem).
One question I'd like to see answered in the future is something that many volcanologists have been (and are still) trying to figure out: What does the inside of a volcano really look like?
Early scientists thought that volcanoes were the homes of gods, or passages to Hell, or conduits for a vast network of subterranean fires. (At left is Athanasius Kirchner's 1664 engraving of the interior of Mount Vesuvius, from his book Mundus Subterraneus. Image from Art.com.) These ideas have all fallen by the wayside, but volcanologists today are still trying to work out the details of volcano 'plumbing', as it's commonly called.
This is no easy task. For one thing, there are many different kinds of volcano; it stands to reason that they're not going to have similar plumbing systems or structures. For another, if you're interested in what's going on inside an active volcano, it's understandably a little difficult to get close enough to the object in question to even begin to work on the question.
So how do volcanologists know anything at all about the interior of volcanoes - and how can they find out more?
One of the easiest ways is to look for volcanoes that are no longer active, and have been worn down by time and erosive forces. There are actually some great examples of these: The Summer Coon volcano in southern Colorado, which shows a spectacular radial pattern of dikes (see the Google Earth image at right); the cinder cones in the Southwestern Nevada Volcanic Field, which one of my professors studies (Keating et al., 2008); even my own study area, at the Santa Maria volcano in Guatemala, has a spectacular view of the internal structure of a stratovolcano (revealed by the 1902 eruption that blew a huge crater in the side of the mountain).
Another way is to use geophysical or remote sensing methods. Volcano seismology (including 3D seismic tomography, sort of a CAT-scan for volcanoes) has been used for years to locate and define the shapes of magma chambers under volcanoes, as well as the dikes and conduits which feed eruptions. For smaller edifices, methods such as ground-penetrating radar can give some idea of the shallow structure. Some researchers in Japan (Miyamachi et al., 1987) have even used explosions from fireworks to image the interior of lava domes (using the shock of the fireworks explosions to take the place of seismic shocks). GPS, ground tilt, and other deformation measurements give volcanologists an idea of how a volcano changes shape and volume, and from that some idea of the internal workings of the volcano can be discerned.
One interesting study by researchers in Japan (Sakuma et al., 2008) details a project where volcanologists actually drilled into an active volcano - Mount Unzen, which last erupted in 1996 and produced a summit lava dome. The Japanese volcanologists found a conduit with several feeder dikes, showing that Unzen's eruption wasn't fed by a single tube but several, and possibly from many sources. Still, this is only a small part of the volcano, and it's a very expensive and tricky way of finding things out.
Because of these methods, we know something about the interior of volcanoes. For example, the old chamber-conduit-summit eruption model for stratovolcanoes is, we now know, an extremely simplistic and not entirely correct view; many stratovolcanoes are riddled with dikes and smaller pockets of magma and other interesting things like cryptodomes. And they're hardly ever as nicely layered as this image suggests. (From the USGS Eastern Geographic Science Center Volcanoes! teacher resource.)
And hey, maybe I'm being pessimistic and someone will invent a whole-body-scan for a volcano. It could happen...
Additional reading:
Keating, G.N. et al., 2008, Shallow plumbing systems for small-volume basaltic volcanoes. Bulletin of Volcanology, v. 70, p. 563-582.
Miyamachi, H. et al., 1987, Seismic experiments on Showa-Shinzan lava dome using firework shots. Pure and Applied Geophysics, v. 125, no. 6, p. 1025-1037.
Poland, M.P. et al., 2004, Patterns of magma flow in segmented silicic dikes at Summer Coon Voclano,Colorado; AMS and thin section analysis. Earth and Planetary Science Letters, v. 219, p. 155-169.
Sakuma, S. et al., 2008, Drilling and logging results of USDP-4; penetration into the volcanic conduit of Unzenvolcano, Japan. Journal of Volcanology and Geothermal Research, v. 175, p. 1-12.
Subscribe to:
Posts (Atom)