Wednesday, April 28, 2010

Scientists study 'glaciovolcanoes,' mountains of fire and ice, in Iceland, British Columbia, US

Science Daily: Glaciovolcanoes, they're called, these rumbling mountains where the orange-red fire of magma meets the frozen blue of glaciers. Iceland's Eyjafjallajökull volcano, which erupted recently, is but one of these volcanoes. Others, such as Katla, Hekla and Askja in Iceland; Edziza in British Columbia, Canada; and Mount Rainier and Mount Redoubt in the U.S., are also glaciovolcanoes: volcanoes covered by ice.

"When an ice-covered volcano erupts, the interplay among molten magma, ice and meltwater can have catastrophic results," says Sonia Esperanca, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funds research on glaciovolcanoes.

In Iceland last week, scientists were well prepared for the floods, called "jökulhlaups," that can happen after a glaciovolcano blows and melts its glacial covering. The floods were followed by tons of ash ejected into the atmosphere. Most of the rest of the world, however, was unaware that an eruption from a small, northern island in the middle of the Atlantic Ocean could freeze air transportation and stop global commerce in its tracks.

That, say NSF-funded scientists Ben Edwards at Dickinson College and Ian Skilling at the University of Pittsburgh, is the nature of glaciovolcanoes. Understanding volcano-ice interactions occupies much of Edwards' and Skilling's daily lives. They're working at Mt. Edziza in British Columbia, Canada, and in Iceland to find out how glaciovolcanic deposits--rock fragments strewn for miles after an ice-covered volcano erupts--are formed….

This image shows both the eruption plume and the heat signature of lava at the volcano’s summit and at nearby Fimmvörduháls, the site of a precursor eruption. The heat signature shows a rough estimate of temperature, with yellow being hottest and red coolest. The signature at Eyjafjallajökull is a concentrated circle without a river of lava, supporting the Icelandic Coast Guard’s observation that lava had not started to flow from the volcano. Image from NASA

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