Sensors Showed Great Seismic Activity at Grímsvötn Skip to content

Sensors Showed Great Seismic Activity at Grímsvötn

By Iceland Review

GPS sensors located near the volcano Grímsvötn on Vatnajökull picked up seismic movement of 50 centimeters in the area when the eruption started there in the evening of May 21. In the future, such sensors could indicate whether and when volcanic eruptions are to be expected.


The eruption in Grímsvötn. Photo by Patrick J. Dorflein.

“In the first two days this sensor moved 50 centimeters towards the center of the crater and 25 centimeters down,” geophysicist Sigrún Hreinsdóttir told

She explained such movements can indicate from which direction magma is flowing. The incident is being investigated; it appears that the magma chamber was shallow.

The GPS sensor sends signals every second and Hreinsdóttir said that between 7 and 8 pm on May 21 there was a lot of activity in Grímsvötn. “We are looking at 50-60 centimeter movements, up and down, north and south, in a very short time span.”

Also in the Grímsvötn eruption, a new radar located at a 70-kilometer distance from the volcano played a key part in analyzing the ash plume emitted from the crater.

Geirfinnur Sigurdsson, an engineer at the Icelandic Meteorological Office, told that the radar made it possible to determine how high the ash plume was with much more accuracy than what has been possible until now.

The radar, which is an Italian design, and new measuring equipment which the Meteorological Office borrowed from the UK and placed at Keflavík International Airport helped predict the distribution of the ash and thereby saved European airlines significant expenses.

Click here to read more about the Grímsvötn eruption.

Please note: The next issue of the print edition of Iceland Review will include extensive coverage of the eruption. If you subscribe now, you will receive a photo book by IR editor/photographer Páll Stefánsson of the eruption in Eyjafjallajökull as a gift.

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