A magnitude 5.4 earthquake occurred at the south edge of Bárðarbunga at 8:03 this morning. The activity is thought to be related to the caldera that has been formed in the glacier this morning.
The specialist on duty at the Icelandic Met Office filed this report at 7:20 am:
"Around 450 earthquakes have been detected since midnight 29/30 August until 07:00, the vast majority in the northern part of the dike intrusion, see maps.
The active part of the dike intrusion extends from about 4 km south of the glacier margin of Dyngjujökull to the location of yesterday's fissure eruption. Only a few small earthquakes have been located north of the eruption site and there is no sign now of northwards migration of the intrusion. Strongest events in this area were M2.7 at 03:01 and M2.8 at 06:19.
Several events have been detected on the caldera rim of Bárðarbunga, strongest were M4.5 at 02:35 and M4.2 at 06:18, both on the northern rim. A magnitude M5.4 earthquake occurred at 07:03 at the southern rim of Bárðarbunga caldera. Several events of similar size have occurred around the caldera rim in recent days. They are interpreted as possibly being related to subsidence of the volcano due to volume decrease in the magma chamber beneath.
A few small events were detected around Askja volcano.
Summarizing, no significant changes in seismic activity have been observed."