A few earthquakes were observed in the caldera of the night. The largest measured 3.5 on the Richter scale, at 02:23. Then there was another tremor a few minutes later, at 02:27. The rate was 3.1 points. This comes out in the Notice from IMO.
There has been inflation in the area around the Bárðarbunga caldera in recent months, fueling a dynamic collection of the caldera. Having evidence of this has been increasingly evident. Such expansion, however, is said to be common in the vicinity of the volcano after the eruption.
The large central volcano of Bárdarbunga lies beneath the NW part of the Vatnajökull icecap, NW of Grímsvötn volcano, and contains a subglacial 700-m-deep caldera. Related fissure systems include the Veidivötn and Trollagigar fissures, which extend about 100 km SW to near Torfajökull volcano and 50 km NE to near Askja volcano, respectively. Voluminous fissure eruptions, including one at Thjorsarhraun, which produced the largest known Holocene lava flow on Earth with a volume of more than 21 cu km, have occurred throughout the Holocene into historical time from the Veidivötn fissure system. The last major eruption of Veidivötn, in 1477, also produced a large tephra deposit. The subglacial Loki-Fögrufjöll volcanic system located SW of Bárdarbunga volcano is also part of the Bárdarbunga volcanic system and contains two subglacial ridges extending from the largely subglacial Hamarinn central volcano; the Loki ridge trends to the NE and the Fögrufjöll ridge to the SW. Jökulhlaups (glacier-outburst floods) from eruptions at Bárdarbunga potentially affect drainages in all directions.
December 21, 2015. Bárðarbunga , Iceland :
Source : OMI , GVP
Photo : Archives Visir ( 09/2014)