Iceland's Met Office raised the risk imposed by the Bardarbunga volcano on the aviation industry to orange, which is one level below the highest possible.
In 2010 ash from Iceland's Eyjafjallajokull volcano shut down most of Europe's airspace for a grand total of six days, costing over $1.7 billion, Reuters reported. Since Aug. 16 seismic activity has been observed in Bardarbunga, causing concern about the possibility of a similar event.
Bardarbunga is Iceland's largest volcano system located under the ice cap of the Vatnajokull glacier. On Monday the Met Office reported the strongest earthquake in the region seen since 1996, which means magma movement is likely.
"As evidence of magma movement shallower than 10 km implies increased potential of a volcanic eruption, the Bardarbunga aviation [color] code has been changed to orange," the Met Office stated according to Reuters. "Presently there are no signs of eruption, but it cannot be excluded that the current activity will result in an explosive subglacial eruption, leading to an outburst flood and ash emission."
The most dangerous part of the activity for Iceland itself is flooding that could be caused by waves from an eruption under any glacier. The area of Iceland that runs the highest risk of flooding is generally uninhabited.
Since the settlement of Iceland in 741, Bárðarbunga is believed to have erupted 43 times Decoded Science reported. Its last confirmed eruption was in 1910, but there have been several occasions where activity has been observed since 1986. In a devastating 1477 eruption may have been larger than the 1980 eruption of Mt. St. Helen.
The Smithsonian Institution's Global Volcanism Program lists 20 volcanic centers on the island, some having multiple possible eruptive sources. In the region there is a "noteworthy" eruption about once every five years.
