Showing posts from December, 2016

Spectacular volcano videos: Identifying eruption processes

- Dr. Janine Krippner We are fortunate that there is a large availability of volcanic eruption videos online for all of us to enjoy (see below warning), and we can learn a lot from them too. When I am looking at my satellite images of dome collapse block and ash flow and column collapse pyroclastic flow deposits on Shiveluch and Mount St. Helens volcanoes I have videos of these processes running through my mind. This is a short guide to what you are seeing in these incredible videos. WARNING: There are very dangerous and life threatening hazards associated with retrieving this footage, and here at In the Company of Volcanoes we strongly discourage anyone from trying to take your own. It is never, ever worth risking your life. --- This video shows the dome at Unzen volcano undergoing a partial collapse in 1991. This shows how a near-solid body of rock rapidly fragments down to smaller pieces of rock and ash, creating a billowing ash plume rising from the block and ash

Interpreting historic eruptions with old dusty hidden treasures: Introduction to historical and social volcanology

Guest Blogger Jazmin Scarlett Follow her on Twitter: @scarlett_jazmin Jazmin shares more of her adventures on her own blog: My name is Jazmin Scarlett, I am a PhD student in volcanology and I am not trained in geology, geophysics or geochemistry. I am trained in understanding hazardous processes and how humans interact with them. I am, therefore, a weird mix of physical and social scientist. I understand the processes behind volcanic activity, but I mainly understand the many characteristics of volcanic hazardous phenomena. I understand how they impact on the natural and built environment and in turn, I understand how humans respond, mitigate and prepare against them. However, the interactions between hazard and person is more often than not more complicated than just hazard + human = impact. As well as understanding the volcano and its hazards, what is around the volcano is just as important. Infrastructure, settlements, topography, climate and

The trees of Calbuco

-Alison Most of my research can be described as looking at rocks to figure out what happened in the past.  There are many deposits from volcanic eruptions that don't just contain rocks. As volcanic soils are very fertile, many volcanoes are forested which means that falling ash or debris flows interact with trees and other plants. The way trees are damaged by the eruption can tell us a lot about what happened. The trees in the blast zone of Mount St. Helens are a dramatic example. Trees blown down by the 1980 later blast at Mt St Helens (image from 2015). I was recently lucky enough to visit Calbuco Volcano in the lake region of Chile. You may remember the impressive pictures of Calbuco erupting at sunset on April 22, 2015.  This heavily forested stratovolcano produced a large plume (which dropped tephra, coarse scoria on the slopes of the volcano and ash all over eastern Chile and Argentina), pyroclastic flows, and lahars (debris flows) from melting glaciers and later