A glacial outburst flood occurred in the river Volga on the edge of Kverkjökull, an outlet glacier in the northern part of Vatnajökull, by the Kverkfjöll mountain range late last week. The flood was accompanied by steam explosions, scattering rocks the size of footballs several hundred meters around the area.
The flood subsided within 24 hours and even though there are no signs of further activity, hikers in the area are asked to be careful, ruv.is reports.
Rangers notified civil protection authorities of a smell of sulfur and increased flow in Volga on Thursday evening. The river swelled to the extent of swallowing a footbridge that lay across it.
On two locations, Kverkjökull lies on top of high-temperature geothermal areas. They cause glacial water to melt and lagoons to form, which at certain points lift the glacier and flood from underneath it.
“There are indications that a glacial outburst flood occurred from a known lagoon called Gengissigið, which is at an altitude of 1,600 meters (5,250 ft) in the high-temperature geothermal area in Kverkfjöll,” said geophysicist Björn Oddsson, project manager at the National Commissioner of the Icelandic Police.
The depression left by the glacial outburst flood is 500 meters in diameter. However, this was considered a minor flood.
“At the bottom of the lagoon we can see brash which had accumulated on the lagoon’s surface and there were also steam explosions in hot springs below the lagoon,” Björn said in description of the scene, which he explored from the air on Friday.
Björn stated that it can prove dangerous to approach Gengissigið because its edges are unstable. “If people are planning hikes to the area, they first have to talk with rangers and seek information from them.”
A glacial outburst flood is expected in South Iceland in the near future.