The Icelandic Meteorological Office (IMO) raised the alert level of the volcano to yellow, as chances that it might erupt have increased following a strong earthquake yesterday.
At about 06:53 local time, a magnitude 4.3 earthquake hit the area of the glacier-covered volcano. The quake is by far the strongest event since the beginning of seismic measurements at the volcano (1991). Over the past few days, a water level started to increase in Gígjukvísl river, which culminated in developing dangerous jökulhlaup (literally „glacial run“), thought to be triggered highly likely by the earthquake. Jökulhlaup is an Icelandic term for glacier outburst – once enough water has accumulated beneath the rims of the glacier, it can lift it and surge out, and/or melt and erode itself a channel through its bottom, to exit in a massive, violent glacial flood. The last glacier run-offs from the volcano within the past two years occurred in October 2022 and November-December 2021.
Glaciologists at the Institute of Earth Sciences at the University of Iceland processed a forecast model estimating a mean discharge rate to be about 0.29 km3/s, which is approx. double the rate in 2022 and third the rate in 2021. The latest measurements estimate forecasts and if continue to be in line with them, the glacial flood will likely reach its peak next weekend. When all water is pouring out, there must be an immense pressure drop.
The latest glacial flood-related eruptions occurred in 2004, 1934 and 1922. On the other hand, the glacial flood-non-related explosion took place in 2011.
Source: Icelandic Met Office volcano activity update 12 January 2024
