Seismic activity in Bárðarbunga volcano continues with a 3.5 magnitude earthquake hitting inside the caldera shortly before 11 am this morning. The biggest earthquake to have hit since the activity started one week ago, 4.7 in strength, occurred last night. The activity is believed to be the result of the caldera sinking because of magma under Vatnajökull glacier.
“The edges sink when magma flows out from a chamber under the caldera,” Gunnar B. Guðmundsson, earthquake specialist at the Icelandic Met Office, explained to ruv.is. “[The earthquakes] are all at a similar depth.”
Gunnar stresses that there are no indications of a volcanic eruption starting. “If the magma breaks through to the surface it will likely happen in Dyngjujökull [outlet glacier].”
One of the theories is that the tunnel, which the magma has formed and is now 25 km (15.5 miles) long, is widening. It lies at a 5-10 km depth in Dyngjujökull, as reported on ruv.is.
Gunnar stated that in the next few days earth scientists will probably be able to estimate whether this will remain a magma intrusion under the glacier or whether it will lead to a bigger event.
“But it’s also impossible to tell,” Gunnar added. “One never knows how these volcanoes will behave.”