The risk of a volcanic eruption in Iceland remains high, and if a fissure opens, lava could reach the Blue Lagoon resort and the Svartsengi geothermal power plant within days, according to an expert. The magma in the 9.3-mile-long magma dike, which formed a week ago, is currently estimated to be 2,600 to 1,640 feet below the surface. In order for an eruption to occur, there needs to be an increase in pressure that allows the magma to move up to the surface and break through the crust.
Although the dike has remained relatively stable in recent days, there is still a significant risk. While some of the magma at the edges of the dike appears to be solidifying, experts from the Icelandic Met Office (IMO) state that the risk has not diminished.
Margaret Hartley, a senior lecturer in Earth sciences at the University of Manchester, believes that an eruption will take place, but the timing is uncertain. She explains that the past six days have been a waiting game, and although the number and intensity of earthquakes have decreased, it does not necessarily mean that the volcanic crisis is dying down.
The dike stretches from Sundhnúk in the north, down into Grindavík and into the sea, meaning an eruption could occur anywhere along its path. Representatives from the IMO suggest that the area north of the town of Grindavík near Hagafell is the most likely place for a fissure to appear.
Alberto Caracciolo, a researcher at the University of Iceland’s Institute of Earth Sciences, explains that initially, a large amount of magma drained into the dike, but it has since stabilized to filling at a constant rate. The dike is now growing and opening up, causing ground deformation on the surface.
Caracciolo believes that if the process continues, the dike will eventually move towards the surface. However, there is currently no indication that the magma is ascending quickly. He predicts that if the magma inflow continues at a constant rate, the dike will reach the surface in the coming days or weeks.
Hartley explains that an eruption occurs when an open fracture connects the magma dike to the Earth’s surface. She compares the process to shaking up a can of fizzy drink, where a crack in the top of the can allows the drink to escape with lots of frothing. When and if lava emerges from the fissure, it is likely to seep out and move across the landscape, similar to the eruption of the Fagradalsfjall volcano in July.
To protect infrastructure, barriers are being erected, and trenches are being constructed to divert lava flows. However, there are still uncertainties about what may happen next. Caracciolo suggests that depending on the specific location of the fissure, the magma output rate, and the duration of the eruption, lava flows could reach the power plant, the Blue Lagoon, and Grindavík within a few days.
