Friday, June 25, 2010

Los Alamos & environs

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

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

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

A vesicular example of the tuff:

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

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

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

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

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

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

Saturday, June 19, 2010

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: 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!

Friday, June 18, 2010

Volcano Vocab #5: Caldera

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

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

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

VEI figure from the USGS Volcano Hazards Program Photo Glossary.

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

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

View Larger Map

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

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

Tuesday, June 15, 2010

Guest Post at "The Plainspoken Scientist"

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

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

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

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

Saturday, June 5, 2010

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

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

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

Thursday, June 3, 2010

Perception of volcanic hazards in Iceland

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

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

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

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

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

  • Many residents did not receive notice of the evacuation, but about 65% of the local population still registered at evacuation centers. Some of the reasons cited by the remaining 35% for their non-participation included lack of communication from officials, reluctance to leave their livestock, or that they were simply not interested in the drill. The response from those who did participate, however, was overwhelmingly in favor of the drill.
  • 71% of evacuation participants were able to correctly describe the evacuation procedures they were supposed to follow during the drill, and 94% were able to define what a jökulhlaup was (and knew that it was the major hazard associated with an eruption of Katla).
  • Many of the residents of towns on higher ground stated that they would remain in their homes rather than evacuate, citing that it was safer there than on roads and that they thought the flood stage of the glacial drainage would be too low to reach them.
  • Many of those surveyed - especially farmers - did not think that 30 minutes was enough time to prepare for an evacuation, since they had livestock to care for in addition to dealing with their homes and families.
  • "None of the participants from the 18–30 year age group and very few from the 31–50 year age group could correctly describe a brief volcanic history of Katla." Some residents who had family members who had seen the 1918 Katla eruption had knowledge of what Katla was capable of, but this has apparently not been passed down to their children.
This paints an interesting picture. Most of the residents, even if they didn't participate in the drill or completely understand the potential hazards associated with an eruption of Katla, were still very well informed about what they should do in an emergency. Many evacuated even though they didn't receive a direct message from emergency officials (mostly because of community volunteers who helped spread the word of the drill). But it is troubling that a large number of people living near Katla (and Eyafyallajökull) knew very little about the past activity of the volcanoes. This is often the case when volcanic disasters have passed partially or completely out of living memory, but given that volcanic activity is extremely common in Iceland, it's not particularly reassuring. The authors suggest that a lack of outreach by public officials may be the cause for this:

Our participants are aware of jökulhlaup, tephra, lightning and rock fall hazards but they have not been provided with enough information to enable them to make an informed decision on whether to evacuate or take shelter in place and how to best protect their livestock.
Finally, the authors comment on some of the underlying problems with the evacuation itself, most having to do with communication issues (again):

Results from our study highlighted problems associated with communication during the evacuation exercise and the possible need to find alternative modes which do not rely so heavily on technology. In light of this, scientists and emergency management officials should collaborate with media agencies and the public in order to promote the use of media resources and, to ensure hazard information is accurately distributed in an understandable form. Furthermore, the importance of the sweepers’ role during an evacuation should be emphasised as they may provide the only communication link between emergency management and farming communities. Recent public meetings which involved residents in risk mitigation efforts are a positive step toward empowering residents with evacuation procedures and preparedness strategies.
What's the bottom line? It's an interesting one: people near this volcanic center in Iceland seemed to be fairly well informed about what they should do in an evacuation. But they weren't necessarily as knowledgeable about the hazards that necessitate the evacuations, even though they live very close to an active (and now erupting) volcanic center. (Given the recent eruptions, I suspect that a follow-up study would show a distinct change in this observation. If anyone comes up with one, I'd be interested to see it.) This study does emphasize again the importance of good communication between scientists, emergency officials and the public; in an emergency, if people are better informed about hazards and what they should do to avoid them, evacuations will run more smoothly and officials will waste less time dealing with confusion and misinformation.

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