Volcanic mountains

M3.6 earthquake by Grímsvötn volcanic system

Grímsvötn lakes in the foreground and Grímsfjall mountain behind them.

An earthquake of

magnitude 3.6

struck the volcanic area of ​​Grímsvötn, under the ice cap of the Vatnajökull glacier, at 6:16 a.m., according to


. A few aftershocks of magnitude greater than 1 followed.

A glacial flood, aka jökulhlaup, from Grímsvötn peaked yesterday morning when the flow of the Gígjukvísl River reached a maximum of around 2,800 m3/sec., or 28 times the average flow of the river at this time of year . Still, the peak flow is considerably lower than originally predicted when scientists estimated the figure at 5,000 m3/sec.

The ice sheet on the Grímsvötn lakes has


a total of 77 meters, and for a few hours it has been subsiding very slowly, which means that the lakes have almost completely emptied of meltwater.

The question now is whether the glacial flood will be followed by a volcanic eruption at Grímsvötn.

There are no signs of volcanic tremor, said Bjarki Kaldalóns Friis, natural hazard specialist at the Icelandic Met Office.


this morning.

The M3.6 quake was preceded by a tremor a minute earlier that measured 2.3. No gas was detected. Bjarki estimates that there is a one in two chance of an eruption at Grímsvötn. The area is closely monitored.

If an eruption followed the jökulhlaup, it wouldn’t necessarily happen right away. “In 2010, six months passed before an eruption started, while in 2004 it happened when the jökulhlaup was about to peak,” Bjarki explains.

“The Grímsvötn volcanic system is ready for an eruption, but the question is whether it is capable. At the moment there is no data available to suggest an eruption is imminent, but that could suddenly change,” Bjarki said.


during an interview last night.