September 17, 2010

Iceland Eruption Ash Cloud Was Not The Norm

Experts say that another volcanic eruption on Iceland could happen again soon, but will likely cause much less chaos than the one that caused air traffic to shutdown earlier this year.

The Eyjafjallajokull volcano, which began erupting on April 14, spewed enough ash into the atmosphere to cause the largest-scale European airspace shutdown since World War II.

University of Iceland geologist Armann Hoskuldsson told an international conference in Keflavik that the event "was very unusual."

"Most volcano eruptions in Iceland are basaltic," with lava flows and spewing only coarse-grained and heavy particles, he explained.

That is what experts expected would happen in Katla, Eyjafjallajokull's neighboring volcano, which is much larger and historically erupts within a year or so of Eyjafjallajokull, said Hoskuldsson.

But the smaller Eyjafjallajokull volcano, whose ash affected more than a hundred thousand flights in April and May, was very different, he insisted. "The particles were so fine that they did not settle. They were absolutely not coming down," and they were determined to travel to Europe, he pointed out.

Other experts at the Keflavik conference agreed that Iceland's next eruption would most likely be less chaotic and not have the same characteristics as the last eruptions.

"No two volcanoes are the same and no two eruptions are the same," said William Aspinall, a geophysicist at Britain's University of Bristol.

For European airspace to suffer similar consequences as last time, the next eruption would need to be as explosive as the last eruption and meteorological conditions would also need to follow similar patterns, he said.

"The conditions have to be right. The volcano has to erupt at the right time, the wind has to blow in the right direction, stay in the right direction for a right amount of time to get the conditions we had," with Eyjafjallajokull, he told the conference.

"For the UK, if we had a repeat of this it would be an absolute disaster if it happened in the next two years," he said, noting that another massive airspace shutdown could seriously disrupt the 2012 Olympics in Britain.


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