Iceland’s Biggest Volcano Under ‘Close Watch’ as Tremors Calm

Seismic activity in Iceland’s largest volcano subsided overnight after it was rocked by the largest tremors in decades to start the week.

One minor quake shook Katla early on Tuesday, after tremors measuring more than 4 in magnitude rocked the crater of the volcano early Monday, Gunnar Gudmundsson, a geophysicist at Iceland’s Met Office said by telephone. It’s under “close watch,” he said.

"People have been waiting a long time for a major Katla eruption," he said. “It has a major eruption every 50-100 years and the last major one was in 1918. There are, however, no signs now or yesterday that there was any magma making its way to the surface."

An eruption of the Eyjafjallajokull volcano in 2010 caused the cancellation of more than 100,000 flights across Europe on concern that glass-like particles formed from lava might melt in aircraft engines and clog turbines. Historically, Eyjafjallajokull has been known to erupt one to two years prior to Katla.