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28 November 2012
A quick note for today: It appears that activity at the Santiaguito lava dome complex in Guatemala has increased significantly, with collapses occurring at the lava flow on the southeastern flank of the Caliente dome. Plumes are visible on GOES satellite images and are reaching 5 km in height (plumes from ash-and-gas eruptions of Caliente are usually less than 1 km high).
26 October 2012
Today is the 110th anniversary of the second-largest eruption of the twentieth century – and if you don’t normally read this blog, it’s a good bet you’ve never heard of it. I’ve written about it before, but never on the date of the event! The culprit? Volcan Santa Maria in Guatemala. In October of 1902, following several months of significant earthquakes, Santa Maria experienced a VEI 6 Plinian eruption that completely devastated the countryside for miles around (much of it was, as it is now, covered with coffee plantations and small farms).
22 February 2012
My choice of favorite geologic illustration, for Accretionary Wedge # 43, comes from a book that geobloggers (and others) have written about in the past: Sir William Hamilton’s Campi Phlegraei, Observations on the Volcanoes of the Two Sicilies. I won’t repeat all the background about Hamilton, who was a British natural historian who observed eruptions of Mount Vesuvius in the 1760s and 1770s. Campi Phlegraei, a three-part work, contained wonderful descriptions of the volcanoes and eruptions of Naples and Sicily, including the 1779 eruption of Mount Vesuvius (discussed and illustrated in a supplement to the first two volumes).
21 December 2011
Ron Schott is hosting Accretionary Wedge #41, and he’s asking us to do a little reminiscing:
Right, then. Your mission, should you choose to accept it, is to relate the story of the most memorable or significant geological event that you’ve directly experienced.
What we seek for AccretionaryWedge #41 is an account of a geologic event that you experienced firsthand. It could be an earthquake, a landslide, a flood, a volcanic eruption, etc. (but don’t feel compelled to stick to the biggies – weathering, anyone?) – some geologic process that you were able to directly observe and experience.
16 December 2011
As per the usual pattern of AGU blogging, I’ve been trying to get caught up with other things after returning from AGU, so naturally I’m only getting to writing about the meeting a week after it happened. I’d better finish this up at some point, so I’ll combine Thursday and Friday’s activities into one post (and then move on to posting photos from San Francisco, which has some fabulous geology that I finally got to check out in my spare time).
20 October 2011
I’ve been going through some rather old papers for the background of a manuscript I’m working on, and I’ve been finding that it’s pretty fun to read about volcanic eruptions from the perspective of early twentieth-century geologists (and non-geologists). My field area in Guatemala wasn’t considered active until Volcan Santa Maria suddenly erupted in 1902, so most people who lived there weren’t really familiar with volcanic phenomena. There weren’t any geoscientists who directly observed the eruption , but they made it to the volcano pretty quickly afterward, and collected accounts from local people to supplement their notes.
When I read these accounts, the first time through I imagine what the writers were seeing – and then the second time through I translate the account into modern terminology. One paper that this was particularly useful for is an account of the eruption written by Gustav Eisen, a Swedish PhD in biology/zoology who was living in Guatemala. Dr. Eisen is very descriptive, but to be useful for my current research, his writing needs a little interpretation. Here are some of my favorite passages, and my “translations” of Eisen’s descriptions into current terminology.
20 September 2011
So in my newsfeed today, an article popped up about Utah petitioning the EPA not to have smoke from July 4th fireworks included in their monitored air pollution (i.e., the amounts that will get you fined if they spike). The article went on to mention that the EPA grants exemptions for spikes in air pollution that result from “exceptional” events, which are defined as follows:
(i) Affects air quality; (ii) Is not reasonably controllable or preventable; (iii) Is an event caused by human activity that is unlikely to recur at a particular location or a natural event; and (iv) Is determined by EPA through the process established in these regulations to be an exceptional event.
These include natural disasters like storms, seismic activity, floods, wildfires and volcanic eruptions, as well as some allowances for air pollution blown in from elsewhere or resulting from terrorism or war.
13 September 2011
This summer, while I was out in New Mexico, I went to the International Folk Art Market in Santa Fe, which is hosted on Museum Hill, Santa Fe’s equivalent of the National Mall. As part of the festival, attendance at all of the museums was free, and I took advantage of the chance to visit a unique exhibit and hear one of the visiting folk artists speak about his work.
The Museum of International Folk Art was hosting the exhibit, entitled “The Arts of Survival: Folk Expression in the Face of Natural Disaster”; the concept behind it was to display art that came about as a result of natural disasters. In this case, four events were represented: Hurricane Katrina in 2005, the flooding in Pakistan in 2010, the January 2010 earthquake in Haiti, and the 2010 eruption of Merapi. Being a volcanologist, I was particularly interested in the Merapi part of the exhibit – and lucky enough to be there on a day when the artist, Tri Suwarno of Java, Indonesia, was available to speak about his volcano-inspired shadow puppets.
17 August 2011
Last week I happened to be watching the National Geographic Channel and caught their new program, “How to Build a Volcano”. Being somewhat interested in volcano-building processes myself, I sat down with a pad of paper and got ready to take notes for a review.
The show started off with an exciting idea: bring together a special effects team and a group of volcanologists and try to replicate volcanic processes on a large (but controllable scale). Thus, building a volcano. The four volcanologists (Mike Manga and Ben Andrews of UC Berkely, Josef Dufek of Georgia Tech, and Ed Llewellyn of Durham University) worked with special effects expert Max MacDonald to create a 10-meter-high volcano in a Canadian quarry (and we all know from Mythbusters that anything involving an abandoned quarry is also going to involve explosions).
18 June 2011
Well, ash-flow tuff got taken pretty quickly, but I’m fairly certain no one will come up with my favorite geology term (or the particular meaning I’m going to talk about). That word is autobrecciation. I’m not talking about the autobrecciation that happens when the surface of a lava flow breaks up and gets incorporated into a lava flow, but the meaning used in several volcanology papers about rockfalls and lava dome collapses: volatile-rich, pressurized lava dome rocks fragmenting explosively in response to rapid decompression, which occurs at a critical pressure difference between the overpressurized rock and the surrounding environment (i.e., the point when the pressure overcomes the tensile strength of the rock). As you can see in the video, the rocks basically disintegrate into a lot of fine material (and probably some leftover rock chunks), which is the perfect recipe for a pyroclastic flow.
23 March 2011
Statistical analysis and volcano monitoring has established that there are both eruptions which were likely triggered by large earthquakes, and given us some plausible mechanisms for how this might happen, although this is still a rather rare event. Ron Schott brought up an interesting point in a comment, however: The mechanisms that I discussed are generally regarded as operating in the short-term – i.e., a few days to weeks after an earthquake (perhaps even a few months). But what about long-term earthquake triggering – are there connections between volcanic eruptions and earthquakes which happened years before? Are there any plausible mechanisms for long-term triggers, and how would they operate? I did a little research to see if I could find answers to either of these questions.
12 March 2011
The geoblogosphere – and the rest of the news – have been buzzing with information and discussion about the recent M8.9 earthquake in Japan. Despite being a country that is relatively well-prepared for events like these, even Japan couldn’t withstand the power of such a quake and the resulting tsunami, and they will need help. Please consider donating to a relief organization such as the Red Cross, Doctors Without Borders, …
13 February 2011
Jim Lehane at The Geology P.A.G.E. is hosting this month’s Accretionary Wedge, and asks:
What geological concept or idea did you hear about that you had no notion of before (and likely surprised you in some way)?
I can’t think of any particular moments where something like this hit me all at once, but one concept that I’ve encountered as a grad student strikes me as something that I never really thought about much as an undergrad (or as a kid who liked volcanoes, for that matter). It’s the idea that an eruption style at a single volcano – not just in a region – can change dramatically in a relatively short period of time.
20 November 2010
One of the things that I come across when I’m working on my thesis is details about how much lava is being produced at a volcano (usually in a volume flux, such as cubic meters/second). In my case, it has to do with how quickly a lava dome is growing, though this also applies to more fluid eruptions as well. But it can be hard to put these numbers into …
9 November 2010
Volcanoes have been getting a lot of media attention this year, which is not surprising; natural disasters make for exciting stories. But your average reporter is likely not going to hold themselves to the same standards of research that science writers do, which ends up being detrimental to everyone, including their readers. Part of this may be because natural disaster stories are quickly written and not well fact-checked in an …
6 November 2010
One of the sad – but not unexpected – stories to come from the eruption at Mount Merapi concerns the death of the “Gatekeeper” of the volcano, Mbah Marijan. Marijan was mentioned in a 2008 National Geographic article, “The Gods Must Be Restless”, that I blogged about a long time ago – and that has turned out to be depressingly prophetic.
30 September 2010
Guest post by Erik Klemetti, assistant professor of Geosciences at Denison University. I started blogging out of frustration with the lack of knowledgeable commentary on volcanic eruptions on the Internet in early 2008. It all came to a head when a mystery volcano in southern Chile erupted (this turned out to be the eruption of Chaitén). I searched in vain for some place that was collecting the unfolding information on …
5 June 2010
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 …
5 March 2010
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 …
27 March 2009
If seeing this first thing in the morning doesn’t both make you want to jump up and down in excitement AND say, “Oh, shit, I just spent the entire night unconscious and three klicks away from an erupting volcano,” you are either clinically dead or an alien. A composite of Santiaguito, gently steaming in the 6AM sunlight. This is both a fascinating and depressing time – fascinating because I could …