An expert from the Icelandic Meteorological Office warns of the possibility of another magma intrusion and subsequent eruption near Grindavík, as magma continues to accumulate under Svartsengi. Recent volcanic activity has created a new subsidence valley in Grindavík, making the town as hazardous as it has ever been.
Another magma intrusion likely
The eruption that began last Sunday on the Reykjanes peninsula can be said to have ended with the last lava spewing shortly before 1 AM on Tuesday. Land uplift continues at a similar pace in the Svartsengi area and magma accumulation, too.
In an interview with RÚV yesterday, Kristín Jónsdóttir, department head of volcanism, earthquakes, and geodynamics at the Icelandic Meteorological Office, stated that as long as magma continues to accumulate, there is a chance of another magma intrusion, and, thereby, another eruption.
“As long as the magma accumulation continues unabated, there is a likelihood of another magma intrusion. But when that will happen is, of course, uncertain. But now, this has been a fairly regular event since about November 10, approximately every month. So, it’s a question of whether or not that’s what we are seeing,” Kristín stated.
Kristín noted that if enough magma accumulated under Svartsengi, it would begin to flow eastward under the Sundhnúksgígaröð range, the site of the last two eruptions. She also explained how the magma had moved during the latest volcanic events.
“On November 10, of course, this very large magma dyke formed, 15 km long. On December 18, the magma moved north along the dyke, and on January 14 it moved south. It’s just a question of what happens next,” Kristín noted, adding that changes in Grindavík during the eruption last Sunday were no less significant than when the magma dyke formed on November 10.
“There will be displacement and, in fact, subsidence where the magma moves closer to the surface. And we see this clearly. An aerial measurement was carried out on Monday, and then both the lava breadth and this subsidence depression are very clearly seen in these measurements.”
Rising hazard in Grindavík
On a new map based on the Meteorological Office’s map of January 16, 2024, a new subsidence valley to the east of the older subsidence valley is visible. This subsidence valley stretches over the eastern part of the town, southward, and down into the sea. The eruption on Sunday occurred to the west of this subsidence valley.
“The results demonstrate that there are cracks that have also formed in the eastern part of the town. These are, of course, old cracks, but they have been strained. And there has been a subsidence of over a metre in the eastern part of the town,” Kristín noted.
The widening in the new subsidence valley amounts to 1.4 metres. As noted by RÚV, scientists believe that as much magma flowed under Svartsengi into the magma dyke on Sunday as happened in the eruption on December 18.
Kristín emphasised that there was great uncertainty regarding what would happen next: in the event of another magma intrusion, would the magma flow north or south, and would that lead to another eruption.
When asked by RÚV whether it would be accurate to state that since the eruption on Sunday the town of Grindavík had never been as hazardous, Kristín concurred. “Yes, I would say that,” she stated.
As reported by RÚV this morning, hot water was restored within the eastern part of Grindavík last night. This morning, workers from the utility company HS Orka, aided by rescue workers and the police, will inspect whether there is heat in the buildings in Grindavík. Residents will not be allowed to retrieve their belongings today.