Bárdarbunga (Iceland): The intense seismic crisis caused by a significant laterally migrating magma intrusion continues to evolve with little changes.
Earthquake activity has been a bit weaker yesterday, only to pick up again today. Two more magnitude 5+ quakes occurred after midnight near the caldera of the Bardarbunga central volcano.
The intrusion is now 45 km long and roughly 20 km deep, but so far remains mostly below 5 km depth. Horizontal spreading between the Dyngjuháls (DYNC) and Kverkfjöll (Gengissig, GSIG) GPS stations approaches 50 cm.
At the moment, the expected most likely outcome scenario is a moderate to large fissure eruption, should the dyke eventually breach surface. The question is when this will occur, and where the magma exactly will be coming from:
According to the Icelandic Met Office, approx. 50 million cubic meters of magma have been added to the current intrusion during the past 24 hours. This corresponds to an average of approx. 500-600 cubic meters a second!
Seismic activity remains high with no signs of weakening. If the intrusion breaches the surface, the most likely scenario seems to be a fissure eruption at the present location of the northern end of the dyke, i.e. immediately north of the Dyngjujökull glacier.
The earthquake this morning at the north/northwestern part of the caldera at 6 km depth at 01:26 UTC could have been the biggest in the current swarm. Estimated magnitudes range from 4.1 (IMO) to 5.7 (USGS).
The magma intrusion (dyke) north of Dyngjujokull is still migrating and stretches now approx. 10 km outside of the glacier.
It will be interesting to see what happens when it reaches the area of the Asjka fissure swarm. A possibility could be that older dykes from that one stop the propagation of the Bardarbunga intrusion, another that it activates Askja as well.
The seismic swarm continues to be intense and continues with no significant changes. A magnitude 5 quake occurred this morning 01:26 UTC northeast of the central volcano.
Approx 1500 quakes had been registered during yesterday. The tip of the earthquake cluster has migrated further and is now 6-7 km north of Dyngjujökull glacier below ice-free land surface. According to IMO, there are no signs of an impending eruption as the quakes remain mostly at 5-12 km depth.
Stromboli (Eolian Islands, Italy): (25 Aug) After fluctuating and unstable effusive activity during the last few days, the vent seems to have once again increased its magma effusion rate and triggered a new pathway for the lava to flow down the upper part of the Sciara del Fuoco.
Whilst on the afternoon of the 23rd of August lava was still flowing down from the plateau in much the same location as it had done since opening of the vent on the 7th of August, the overflow of lava from the ca 600 m plateau onto the Sciara del Fuoco had substantially decreased by the early hours of the 24th of August.
As the hours passed by, the old lava flow dried up and started to cool down despite the fact that effusion from the vent at ca. 650 m seemed to continue. By midday of the 24th, the volume of lava issuing from the vent had even increased – as shown by the thermal webcam image which indicated two, instead of one, branches. Video: