Scientists went on expeditions to the site of the glacial flooding by Mýrdalsjökull glacier in south Iceland last weekend to learn more about the circumstances and take samples of gas and water to determine whether the sub-glacial volcano Katla erupted.

A glacier tour on Mýrdalsjökull. The photo is not directly related to the story. By Páll Stefánsson.

The flood in Múlakvísl occurred on Friday night and caused the Civil Protection Department to declare a level of danger on Saturday morning, Fréttabladid recollects.

First there was a small flood which reached the bridge across Múlakvísl and shortly afterwards the large glacial flood arrived, tearing down the 128-meter long bridge. Trucks and a specialized bus started ferrying people across the river yesterday, ruv.is reports.

The Red Cross opened multi-service help centers in the elementary schools in Vík and Kirkjubaejarklaustur. Approximately 200 people were evacuated from Álftaver, Medalland and Thakgil.

They were permitted to return to the area on Saturday afternoon when the danger level was downgraded to a lower level of uncertainty. Only a part of Mýrdalsjökull is still defined as a danger zone.

The flood originated in three known calderas (not two as reported earlier) in Mýrdalsjökull and one new caldera was formed. The flood also created massive cracks in the glacier.

Earthquake sensors clearly indicated activity as of 8:30 pm on Friday, which increased significantly shortly after 10 pm. Around 5 am on Saturday morning, the activity started subsiding.

Scientists from the University of Iceland Institute of Earth Sciences took samples from the flood water on Saturday and Sunday.

By analyzing the water they hope to find out whether this was just a flood or whether a small eruption occurred underneath the icecap where the volcano Katla lies.

According to Morgunbladid, samples of gas and other chemicals collected by the team of scientists indicate the flood was likely caused by geothermal water. However, an eruption cannot be ruled out.

“The only thing we can be absolutely sure of is that there is a lot of heat underneath Katla and that there is meltwater there, regardless of whether it is geothermal water or whether it was caused by eruptions,” commented Sigurdur Reynir Gíslason, a geochemist at the University of Iceland.

It is also clear that magma is moving but it isn’t certain that it has reached the surface, Gíslason added. There is a sound reason to monitor Katla closely as its eruptions can prove dangerous.

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