Scientists from the Icelandic Meteorological Office and the University of Iceland completed their studies of Öskjuvatn, the crater lake of Askja volcano in the northeastern highlands, on Monday and have concluded that the water temperature could not have caused the lake’s unusual iceless state.

Askja. Archive photo by Páll Stefánsson.

The water temperature was only 1-2°C (34-36°F). However, the temperature at the floor of the lake has not been measured and it is considered possible that inflow of geothermally heated water may have contributed to the melting of the ice, combined with unusual weather, ruv.is reports.

The presence of geothermal heat at the lake’s floor and by its banks is known and has caused holes to appear in the ice on the lake’s surface all winter.

Unusual weather in the highlands consisting of warm southwesterly winds and sunshine may have sufficed to break up the ice and move it around the lake and eventually push it ashore.

Those two factors combined are now believed to have caused all ice to disappear from the surface of Öskjuvatn while other lakes in the highlands remained ice-covered.

However, other data, such as, measurements of the lake’s chemical content, gas convection in the lake, information from earthquake monitors and on movements in the earth’s surface has yet to be processed and so a final conclusion cannot be made at this time.

The expedition’s members are expected to return from the highlands today.

Click here to read more about this story and here to see a video model demonstrating seismic and volcanic activity in Iceland.

ESA