Glacial outburst flood in Southeast Iceland

Photo: Meteorological Office / Benedikt G. Ófeigsson

Since the end of last week a glacial outburst flood, known in Icelandic as jökulhlaup, in Skaftá river, Southeast Iceland began. Over several days the electrical conductivity in the river has gradually been increasing as well as its water level and the smell of sulfur. The Department of Civil Protection has declared the level of danger in the area, several roads have been closed and the situation is being closely monitored.

To place those who are not familiar with the geography of Iceland, this area is located very close to the Vatnajökull National Park and the Skaftafell Protected Area, therefore crossing the main road, known as the Ring Road, where most tourists they drive during their trip.

Map of road closures in Southeast Iceland. Screenshot from www.road.is

The experts from the Meteorological Office yesterday made a surveillance flight over the flooded area to investigate the consequences of the eruption and subsequent flooding, which still cannot really be known until the water withdraws from the flooded areas and returns to the course of the Skaftá river.

A photo from a surveillance flight yesterday and shows running water by the bridge at the top of Skaftárdalur. Photo: Meteorological Office / Benedikt G. Ófeigsson

What is a Jökulhlaup?

It is the Icelandic word used to describe a glacial outburst flood. They are caused by geothermal warming or volcanic eruptions beneath glaciers, although it is also used to describe any large, abrupt release of water from a subglacial lake. When geothermal heat melts the glacier ice, depressions often form in the glacier's icecap, warning of a possible Jökulhlaup. Once the amount of ice that has melted and collected there reaches a certain level, an outburst flood occurs, becoming very destructive in some cases.

Overview of the icecap. Photo: Meteorological Office