An earthquake of 5.4 in magnitude hit the northern caldera rim of Bárðarbunga volcano under Vatnajökull glacier at 1:37 am yesterday. Following the event, seismic activity in the intrusive dike, connecting the volcano with the eruption in Holuhraun, increased slightly.
Similar observations have been made for several previous earthquakes above magnitude 5.0; seismicity often increases slightly in the intrusion for several hours following larger caldera events, the Icelandic Met Office reports.
Since noon yesterday, seismic activity around Bárðarbunga and in the dike intrusion, as well as volcanic activity at the eruption site in Holuhraun, has remained at stable levels. The eruption was clearly visible on cameras throughout the day. It continues with comparable force as in recent days and no changes are visible or reported from the field.
The strongest earthquake at Bárðarbunga yesterday evening was of magnitude 4.8, hitting at 10:27 on the southern caldera rim. Additionally, seven events exceeded magnitude 4.0 and 11 were in the range of magnitude 3.0 to 3.9.
Around 90 events were detected in the Bárðarbunga area in the past 24 hours. In the same period, 25 minor earthquakes were detected in the dike intrusion, none of which exceeded magnitude 1.6. Most quakes were located in the northern part of the intrusion.
Activity around Herðubreið mountain and Tungnafellsjökull glacier was comparably low.
Eruption pollution is expected to the north and east of the eruption site today and tomorrow. Light winds are forecast for both days, increasing the risk of high values of gas concentration.