Askja is a large basaltic central volcano that forms the Dyngjufjöll massif. It is truncated by three overlapping calderas, the largest of which is 8 km wide and may have been produced primarily from subglacial ring-fracture eruptions rather than by subsidence.
A swarm of earthquakes at shallow depths, mostly around 2-5 km has been occurring in an area about 12 km NE of the caldera. 27 quakes including 6 between magnitudes 2.1-2.7 were recorded yesterday.
Time and depth of recent quakes at Askja volcano on Iceland
Tremor signal at Askja volcano (Icelandic Met Office)
During the past days, an increased number of earthquakes occurred in an area east of the Askja caldera. The corresponding tremor signal has been rising as well, although these levels seem not to be alarming.
Location of recent quakes (Sep 2012) at and near Askja volcano
Time and depth of quakes (Sep 2012) near Askja
An increased number of earthquakes can be noted beneath Askja volcano during recent weeks. A shallow M2 quake occurred early this morning at 07:29 GMT.
Earthquake swarm near the Askja caldera on 14-15 May 2012 (Icelandic Met Office)
A small seismic swarm occurred on 14-15 May near the Askja caldera in central Iceland, just southwest of Herðubreið volcano. ...more
Herðubreið volcano, located in the Highlands of Iceland in the midst of the Ódáðahraun desert, is an isolated, table-mountain shaped broad cone that formed beneath the icesheet that covered Iceland during the last ice age, which is when the volcano had its last eruption. Whether the recent seismic swarm is related to the same magmatic system that formed Herðubreið or rather to the larger Askja caldera volcano is difficult to asses. [less]
Some news has appeared about a sudden warming of the Askja volcano caldera lake. It seems that a melt of ice in the caldera lake started in the beginning of March and by the end of March, the lake was completely ice free. ...more
This is highly unusual and it is not known to have happened before. Such increase in hydrothermal activity is probably caused by a heat source at the bottom of the lake, although so far, there are no other changes visible around Lake Askja. Hydrothermal areas around Askja are active recent reports confirm. Whether the raised temperature of Askja lake is a precursor to a new eruption in the foreseeable future is speculation at this point. [less]
