Iceland volcano 'restless' for months

MADISON, Wis., Nov. 18 (UPI) -- The eruption this spring of an Icelandic volcano was preceded by months of geologic unrest as magma flowed through its "plumbing," researchers say.

Researchers analyzing geophysical changes in the long-dormant Eyjafjallajoekull volcano leading up to its eruptions in March and April suggest that magma flowing beneath the volcano may have triggered its reawakening, ScienceDaily.com reported.

"Several months of unrest preceded the eruptions, with magma moving around downstairs in the plumbing and making noise in the form of earthquakes," Kurt Feigl, a professor of geosciences at the University of Wisconsin-Madison, said. "By monitoring volcanoes, we can understand the processes that drive them to erupt."

Feigl and collaborators from Iceland, Sweden, and the Netherlands used satellite imaging and GPS surveys to monitor the volcano.

The volcano swelled for 11 weeks before it began to erupt in March from one side, the researchers found.

"If you watch a volcano for decades, you can tell when it's getting restless," Feigl says.

In late summer 2009, a small shift at a GPS station on the volcano's flank prompted scientists to begin monitoring the mountain more closely.

In early January 2010, the rate of swelling and the number of earthquakes increased, leading up to the first eruption in March.

"We're a long way from being able to predict eruptions," Feigl says, "but if we can visualize the magma as it moves upward inside the volcano, then we'll improve our understanding of the processes driving volcanic activity."