Increased geothermal heat and seismic activity below Mýrdalsjökull glacier in south Iceland, which covers the volcano Katla, may indicate an upcoming eruption. Scientists are closely monitoring the volcano, although it is not certain whether an eruption is imminent.

Mýrdalsjökull and Mt. Maelifell. Photo by Páll Stefánsson.

Geophysicist Magnús Tumi Gudmundsson went on an observation flight over Mýrdalsjökull yesterday. “There is always uncertainty regarding Katla and therefore it was considered necessary to fly over the glacier to shed a light on what is going on,” he told Fréttabladid.

He noted that calderas and cracks in the glacier clearly showed increased geothermal heat and regular series of minor earthquakes also indicate that the volcano has been expanding recently.

Gudmundsson pointed out that there is only one definite indication of an onset of an eruption in Katla . “All sources on Katla eruptions over the past 500 years mention large earthquakes that can clearly be found in Mýrdalur [by Vík] a few hours before the eruption begins. That is in fact the only absolute warning.”

Seismic activity was recorded below Mýrdalsjökull yesterday but this morning it seemed to have subsided. The glacial river Múlakvísl also flooded but the water level peaked yesterday evening and the water flow has since decreased, ruv.is reports.

The calderas which caused the flood in Múlakvísl in July are unchanged but Gudmundsson said there is a new depression in the icecap to the south of them which indicate increased geothermal heat.

He added that there is no clear reason for yesterday’s earthquakes. According to ruv.is, scientists believe water may have caused the tremors, although the tremors were weaker than those that preceded the flood in Múlakvísl last summer.

Since the flood in July approximately 800 minor earthquakes have been registered in the area, compared to 300 last year. Gudmundsson iterated there is good reason to be prepared for an eruption but these series of events won’t necessarily lead to one.

The last large volcanic eruption in Katla occurred in 1918.

Click here to read more about recent seismic activity in Katla.

ESA