Hiding a volcanoTake a good look at this image. This shot was taken in Antarctica, on top of several
Hiding a volcanoTake a good look at this image. This shot was taken in Antarctica, on top of several kilometers of ice. Ask yourself this question…if there was a volcano directly underneath these people…could they know it? A kilometer of ice…some volcanoes might poke through that, but many wouldn’t.Dr. Doug Weins from Washington University in St. Louis might have just found one. As part of one of the investigations of the ice sheet, their research group deployed a series of seismographs on the surface of the West Antarctic Ice Sheet. Seismographs can help monitor the thickness of the ice and how it is flowing, so the deployment wasn’t necessarily there to look beneath the ice.In 2010 and 2011, those seismographs started recording earthquakes. A fairly good number of earthquakes, over a thousand, in one spot under 2 kilometers of ice, 55 kilometers from the nearest known volcano. Movement of magma through the Earth’s crust gives a specific seismic signature, producing small earthquakes just like these, meaning they were likely caused by movement within a magma chamber.Other seismic investigations revealed a strange layer in the ice at this point. It’s buried a kilometer deep, half way between the top of the ice and the ground. Their best explanation for that layer is that it’s ash, frozen in the ice sheet from a major eruption thousands of years ago.A volcano like this can release a lot of heat. Not nearly enough to threaten the entire ice sheet, but enough to melt large amounts of the ice above it. This layer of ash suggests that about 8000 years ago, this volcano underwent a large eruption. Not as large as something like Yellowstone going off, but given the amount of ice it melted, about as large as the 1883 eruption of Krakatoa.A hidden Krakatoa, buried under 2 kilometers of ice with no one knowing it’s there. Fascinating find.-JBBImage credit: Hannes Grobe/AWIhttp://commons.wikimedia.org/wiki/File:White-out_hg.jpgOriginal paper (subscription):http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1992.html__ -- source link
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