Cracking Volcanoes

A selection of the large eruptions that Santiaguito has produced in 2016. Left: 11 April (Source: INSIVUMEH ). Middle: 19 May (Source: INSIVUMEH ). Right: 17 June (Source:  Stereo100Noticias ). Last week Anthony Lamur and I were back in Guatemala to collect more observations from Santiaguito volcano . The fieldwork was prompted by the occurrence of several very large eruptions at the volcano in 2016 (like those in the image above), a departure from the regular but relatively small explosions that are typical of the place. What we wanted to know was what mechanism is driving the much larger explosions? Our campsite on Santa Maria on the morning of June 13th. The shadow of Santa Maria (3,772 m high) stretches far into the distance.  Our task for the trip was simple: we would camp on Santa Maria and watch Santiaguito for a few days with optical and thermal cameras to record any explosions. We also deployed a temporary acoustic microphone to record the infrasound prod...

If you have been following myself or Liverpool Volcanology , you will probably know that the group has been carrying out an extensive amount of fieldwork around Santiaguito volcano in Guatemala. You can read about those trips in previous posts  here , by Felix on GeoLog , and an amazing article by Nathanial Hoffman . For this post, I'll be writing about the first of hopefully many articles to come out of our efforts, published in Geophysical Research Letters . A gas-and-ash plume rises from the Caliente vent at Santiaguito in November 2014. The article, put together by Silvio de Angelis , details how we used infrasound and infrared thermal data to characterise small explosions at Santiaguito. This analysis was also complemented by measurements of ash collected after the explosions.  What we wanted to know was: how much ash is in the explosion plume, and how fast and high is it being injected into the atmosphere? Silvio, Armando and Andreas  deploying a stat...

This is a guest post by Becky Coats , a volcanology postgraduate here at the University of Liverpool. She has written about her amazing recent fieldwork to Unzen volcano in Japan!   Meet the A Team: Mission Unzen-Fugen, feat. (left to right, top to bottom) Claire Harnett , Paul Wallace , Dr. Mark Thomas , Dr. Takahiro Miwa , James Ashworth ,  Dr. Jackie Kendrick , Prof. Yan Lavallée , and me! This trip was a collaboration between the University of Liverpool (Jackie, Yan, Paul, James and myself), the University of Leeds (Mark and Claire) and the National Research Institute for Earth Science and Disaster Prevention, Japan (Taka). Those of us from UK universities were in Japan from the 8th to the 20th of May and were granted permission for 6 days work on the lava dome each armed with our own specialist tasks but with one collaborative question: How stable is the dome today? My assignment was to collect samples from a near by pyroclastic deposit that represent the ...

Another week, another cheeky self-promoting post. This time, I have published a new paper in Solid Earth   on my research on the eruption of Unzen volcano in Japan. The project involves a volcanic spine, thousands of volcanic earthquakes, and a whole medley of analytical tools. Interested? Read on... Incandescent glow seen on the newly forming lava dome at Unzen volcano in 1991. Pyroclastic density current deposits can be seen in the foreground. These currents, also known as pyroclastic flows, were derived from collapses of the highly unstable dome. Photo credit: Fumiaki Kobayashi Let's start from the beginning. Lava spines are a curious and spectacular formation found at volcanoes around the world. These plugs of lava are squeezed out of lava domes during eruptions, grinding as they go, and eventually reaching hundreds of metres in size. One such spine grew at Unzen volcano in Japan in 1994, and is the focus of the new paper. Extensive field and experimental investigatio...