آتشفشان ها در زیر پهنه های یخ در ایسلند، کا نادا و امریکا
The combination of hot rock and ice produce a unique set of hazards.
| Where Fire and Ice Meet Glaciovolcanoes, they're called, these rumbling mountains where the orange-red fire of magma meets the frozen blue of glaciers. Eyjafjallajökull is One of Many Glaciovolcanoes 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. Meltwater Floods - Jökulhlaups "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, 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. The Impact on Air Transportation 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. Volcano-ice interaction presents unique types of hazards, say the geologists, but what's left behind after an eruption can also serve as a window into our geologic past. |
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