New Icelandic volcano eruption could have global impact
By Jane O'Brien
1 December 2011 Last updated at 21:16 ET
BBC News, Reykjavik
full story
http://www.bbc.co.uk/news/world-europe-15995845
Hundreds of metres under one of Iceland's largest glaciers there are signs of an imminent volcanic eruption that could be one of the most powerful the country has seen in almost a century. . . .
He says the fallout also depends on the type of eruption and any number of external factors.
"This difficulty is very apparent when you compare the last two eruptions in Iceland - Eyjafjallajokull in 2010 and Grimsvotn in 2011.
"Eyjafjallajokull, which brought air traffic to a halt across Europe, was a relatively small eruption, but the unusual chemistry of the magma, the long duration and the weather pattern during the eruption made it very disruptive.
"The Grimsvotn eruption of 2011 was much larger in terms of volume of erupted material.
"It only lasted a week and the ash in the atmosphere fell out relatively quickly. . . .
But Iceland is unique because it straddles two tectonic plates and is the only place in the world where the mid-Atlantic rift is visible above the surface of the ocean.
"It means you actually see the crust of the earth ripping apart," says Mr Cochran. "You have an immense amount of volcanic activity and seismic activity. It's also at a relatively high altitude so Iceland is host to among other things, the world's third largest icecap."
But the biggest threat to Iceland's icecaps is seen as climate change, not the volcanoes that sometimes melt the icecaps.
They have begun to thin and retreat dramatically over the last few decades, contributing to the rise in sea levels that no eruption of Katla, however big, is likely to match.
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