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16 June 2017

Vacationing at volcanoes: The Toba Caldera

Visiting one of the largest volcanic lakes (and calderas) in the world in northern Sumatra: Toba Caldera


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14 September 2015

Benchmarking Time: California Collection

I’ve been neglecting this series, but I didn’t stop “collecting” benchmarks when I moved to California. In fact, working at the USGS makes it really easy to find markers, because there are at least three on campus.


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23 July 2015

Domes galore: Obsidian Dome, Long Valley

For the final dome in our volcanology day back in my May Long Valley field trip, the W&M students and I took a short hike up to Obsidian Dome. The Obsidian, Glass Creek and Deadman Creek domes all erupted around 1350 CE, which makes them some of the youngest features in the Long Valley area. The three domes are aligned north-south and probably all erupted from the same dike, which …


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28 June 2015

Domes galore: Mono Craters, Long Valley

Being the guest lecturer on a geology trip is great, especially if you get to talk about your favorite geologic features. But what does one do when volcanology day is over and it’s time for the students to do a moraine mapping project? Naturally, sit on a convenient rock and observe some lovely lava domes.


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21 May 2012

Eclipse + caldera = an excellent evening for a volcanologist

I had the excellent opportunity to view today’s annular eclipse from the top of Pajarito Mountain, just outside of Los Alamos, New Mexico. I had the excellent opportunity to view today’s annular eclipse from the top of Pajarito Mountain, just outside of Los Alamos, New Mexico. What an amazing time!


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13 May 2012

Sidetracked: Cave of the Winds, Los Alamos

Well, I had planned to work on my Bancroft posts this week, but in all the packing hoopla I realized that I left my field notes in Buffalo, which doesn’t help me much while I’m here in Los Alamos. So you’re just going to have to settle for some photos from the hike I took yesterday along the Quemazon trail to the Cave of the Winds.


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11 August 2011

What I did this summer:

Went to work at a not-so-super-secret government lab: Got in touch with my inner river rat: Did a little caving: Experienced a natural disaster (not good for my particular natural hazard┬áresearch, by the way): Explored some ruins: Split a few rocks: Drove through a volcano: Drove up a volcano: Put 5,000 miles on the car: Took in some scenery: And came across a W&M alum a bit west of where …


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15 June 2011

Obsidian hunting in the Jemez Mountains

This past weekend I took a day to go revisit the Valles Caldera. While I was wandering the trails, I decided to do a little “rockhounding”. Geologists are often notorious for their rock collections, and I felt like mine was missing something that no volcanologist should be without: Obsidian.

Obsidian is basically volcanic glass – the result of lava cooling so quickly that it doesn’t have time to develop crystals. Pure glass is basically SiO2, and obsidian tends to form from rhyolitic magmas (which already have a high percentage of SiO2, typically greater than 68%). “Heavy” minerals in the obsidian (such as iron and magnesium) make the glass dark, and (depending on their oxidation state) can give it reddish or greenish hues.


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10 June 2011

Valles Caldera

I meant to post this last year after my brief trip to Los Alamos, but now that I’m back on the Hill for the summer, it seems a shame not to show off the scenery!

The Jemez Volcanic Field in northern New Mexico – which includes the Valles Caldera – straddles the Rio Grande Rift in the east and the Colorado Plateau in the west. The Jemez contains volcanic rocks erupted from >13 to 0.13 million years ago, with compositions ranging from basalt (low silica content) to rhyolite (high silica). The best known of these is the Bandelier Tuff, a thick sequence of pyroclastic deposits which were erupted in several phases around 1.62 to 1.25 million years ago. The total volume of material in the Bandelier is around 300 cubic km (~75 cubic miles), and it covers much of the area in the Jemez Volcanic Field. (The Bandelier tends to be unwelded and relatively soft, and canyons have cut down through it in many places, creating wonderful vertical exposures as well as the mesas and plateaus that Los Alamos is built on.)


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18 June 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, …


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