It is to be expected that there will be frequent eruptions in the Grímsvötn volcano on Vatnajökull glacier in the coming decades with the series of eruptions peaking around the middle of the century. No volcano has erupted as often in historical times in Iceland.

The eruption in Grímsvötn. Photo by Gyst. Click on the picture to enlarge it.

The Grímsvötn crater is described as a magnificent natural phenomenon on ruv.is.

Underneath the icecap there is a powerful system of geothermal heat which constantly melts the ice and at regular intervals the water bursts out from underneath the glacial dam, causing floods.

Grímsvötn is also Iceland’s most active volcano; in the past 800 years it has erupted approximately 60 times. This means one eruption every 13 years on average.

“The average doesn’t tell the whole story because sometimes there are eruption breaks and it comes in waves. The wave is 130 years so for 40-80 years there is a lot of volcanic activity and then the volcano is quiet in between,” said geophysicist Helgi Björnsson.

Grímsvötn was quiet during most of the 20th century but in the past years it has erupted regularly. Björnsson expects this development to continue.

“What our studies have shown and what we believe will come true is that there will be increased volcanic activity in Grímsvötn until the middle of this century, perhaps peaking mid-century, but then it will subside,” Björnsson stated.

The last eruption in Grímsvötn occurred in 2004, which was not a particularly powerful eruption.

However, in 1998 there was a large eruption in Grímsvötn, which was accompanied by extreme explosions in the crater, although there wasn’t much ash fall in inhabited areas.

In 1983 there was also an eruption in Grímsvötn which was the first since 1938. None of these eruptions were as forceful as the one which is currently coming to an end.

Click here to read more about the eruption in Grímsvötn.