Fundraising update: $10 for Guatemala

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!

The Santiaguito Volcano Observatory needs your help!

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!

Video Friday

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

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

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

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!

Watch your step: Field work on lava domes

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.

Back in los Estados Unidos

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!