Over the last few weeks, a number of you have noted some news from Andean volcanoes that have made it into the mainstream media. The first details the slow but impressive inflation of Uturuncu in Bolivia. This inflation has happened over the course of the last 20 years (at least) at a rate of 1-2 cm of uplift per year. Do the math, and that is 20-40 cm of uplift! This uplift is likely due to the intrusion of magma at depth and could imply that a large reservoir of magma is building under Uturuncu, which is thought to have not erupted since sometime in the Pleistocene (2.6 million to 11,700 years ago). The second piece was on the triggers of supervolcanic eruptions - specifically in the Altiplano-Puna Volcanic Complex in Chile/Bolivia. The new study, presented at the 2011 Geological Society of America meeting, describes the structural and thermal parameters in the crust needed to generate a so-called "supereruption". This work suggests it takes more than just a lot of magma to create the largest explosive eruptions on the planet. What links these bits of news together is one of the experts on volcanism in this part of the world is Dr. Shanaka de Silva, a professor at Oregon State University. He has a hand in both of these areas and has spent much of his career thinking about calderas and "supereruptions", including the 1600 A.D. eruption of Huaynaputina in southern Peru and one of the largest volcanic complexes on Earth. You might be familiar with the work of some of his current graduate students, including Morgan Salisbury who has a guest post on Eruptions in August. He also helps maintain Volcano World and the excellent
Volcanoes of the Central Andes
- a book (and now a website) written by Dr. de Silva and the late Peter Francis that I spent many hours with during my dissertation work. Now, here is your chance to ask him questions about the central Andes, calderas and the biggest eruptions of them - the "supereruptions". So, send me your questions to eruptionsblog (at gmail), tweet them to me @eruptionsblog or leave them as a comment below. I'll compile the questions and send them to Dr. de Silva in early November, so you have a week to send in your questions. Get to it!
