The intense swarm of earthquakes that began near the site of the Fagradalsfjall eruption on the Reykjanes Peninsula, Iceland, on December 21, 2021 – just one day after the official announcement of the end of the eruption – continues without signs of abating.
Although no new lava flows have been detected in the crater over the past three months, the area still continues to rise. The aviation color code remains orange.
More than 5,000 earthquakes have been recorded in the area since the swarm began, most of them below magnitude 3.
In just 48 hours to 10:25 UTC Dec. 24, the Icelandic Bureau of Meteorology (IMO) recorded 2,268 earthquakes in the Reykjanes Peninsula, with the vast majority in the Fagradalsfjall area.
23 of them were magnitude 3 or higher, 259 were magnitude 2 to 3, and 994 were magnitude 1 to 2.
IMO scientists believe the earthquakes are the result of lateral magma movement.
No new lava flows have been detected in the past three months in the Fagradalsfjall crater, but the area is still rising, and scientists are now working to model the processes taking place and determine possible scenarios.
“It can be difficult to say with certainty when an eruption will end because volcanic activity can be erratic,” says Sarah Barsotti, IMO volcanic hazards coordinator2.
“Before the Geldingadalire eruption, the Reykjanes Peninsula was very active in terms of seismic activity and magmatic disturbances. As we know from the past, when the peninsula becomes active again, episodic eruptions can occur in series.”
“We continue to monitor the Reykjanes Peninsula closely, but we can say that the particular eruption that began on March 19 has come to an end. However, even though this episode is closed, we know that activity in the area is still ongoing, and other eruptive phases may begin in the near future,” says Sarah.