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Squink
2015-Sep-15, 03:46 AM
Nice photo essay on ice caves in the summit glacier of Mt. St. Helens (http://www.bbc.com/travel/story/20150326-the-glacier-born-of-fire):

By the late 1990s, scientists with the United States Geologic Survey (USGS) noticed tell-tale signs of glacial advance at Mt St Helens in the form of cracks and crevasses in the snow’s surface. Since then, because of factors such as frequent avalanches from the unstable crater walls, long months of sun protection due to the glacier’s northern exposure, and a heavy, insulating layer of rock separating the ice from the volcano, Crater Glacier has been growing consistently at four inches, and sometimes up to two feet, per day. (Credit: United States Geological Survey)
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In 2012, USGS researchers flying over the crater noticed a gaping hole in the middle of the ice field. Most glacier caves are horizontally oriented, formed by melt water that erodes a tunnel through the underside of a glacier. But here, geothermal activity below Crater Glacier formed vertically oriented caves through a rare combination of hot steam and gas rising through sections of the ice that overlay geothermal vents. (Credit: Eric Guth)

Trebuchet
2015-Sep-15, 02:37 PM
Great story. It makes me sad that it's on BBC instead of the US media, somehow.