A flood has started in Gígja in south-eastern Iceland, but the origin is in Grímsvötn, an active volcano in Vatnajökull. The Icelandic Meteorologist Office detected subterranean disturbances near Grímsvötn lakes on Vatnajökull glacier, south Iceland, on Sunday afternoon causing increased flow of water by 30 cm and electrolytes. However other rivers leading from the glacier, such as Skeidará river, are dry.
“I think we can safely state that Gígja has started flooding,” Gunnar Sigurdsson, hydrologist and engineer at the National Energy Authority told mbl.is. “It may take 4-5 days to reach maxmimum volume.”
Once the water level in Grímsvötn lakes has reached a certain height it tunnels its way down. Sigurdsson said he could not say how the flood would develop. Maybe all the flood would go into Gígja.
Eruption in Grímsvötn in 2004. Matthew J. Roberts, Icelandic Met Office
The volume of water in Gígja Sunday afternoon was about 130 cubic meters per second, and the electrolytic about double what is normal, which according to Sigurdsson is not very much, but might increase. In the next few days scientists will follow Grímsvötn closely, an eruption is not impossible. Grímsvötn usually erupts about every ten years. Grímsvötn are the most active Icelandic volcano.
The Grímsvötn lakes, which lie on top of a large magma chamber of a powerful volcano on Vatnajökull glacier in southeast Iceland, were ranked eighth in the Discovery Channel’s recent listing of the Top 10 Volcanoes in Geologic History.
The video below is from the last eruption in Grímsvötn in November 2004 by Kristján and Fáfnir.
