The rise of the ground near Askja indicates that magma is accumulating beneath it. Freysteinn Sigmundsson, a geophysicist at the University of Iceland, says the process is just beginning. This explains the change in the behavior of the volcano, which has been quiet for the last 40 years.
Askja is a large volcano in Dyngjufjöll with a characteristic silhouette and its caldera measures 50 km2. The bottom of Askja is covered with lava and pumice from numerous eruptions throughout history. Öskjuvatn, the deepest lake in the country (220m deep), was formed in a massive eruption in 1875. Askja’s last eruption was 60 years ago. Activity in this area has been regularly measured since 1983.
“There has now been a change in the behavior of the volcano. After the caldera has been lowered temporarily and the pressure in it has dropped, the pressure begins to rise. The most likely explanation for this situation is the influx of magma to the volcano “ Says Freysteinn Sigmundsson.
“Most of these events only end in the solidification of the magma underground” – he adds.
The ground in the Askja area is rising at a rate of about five centimeters per month, which theoretically means fairly rapid growth. The seismic activity and the amount of geothermal heat released also increased there.
The timescale for how the situation in Askja will develop is weeks, months and maybe even years. The only thing left for us to do is monitor the state of the volcano and not get surprised.
We recommend a documentary about Askja’s activity in 1961.