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. ...plus
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. [moins]
Quelques nouvelles sont apparues à propos d'un réchauffement soudain du lac de la caldeira du volcan Askja. Il semble que la fonte de la glace dans le lac de la caldeira a commencé dans le début de mars et vers la fin de mars, le lac était complètement sans glace. ...plus
Ceci est fortement inhabituel et on ne connaît pas d'évènement similaire produit auparavant. Une telle augmentation de l'activité hydrothermal est probablement causée par une source de chaleur au fond du lac, bien que jusqu'ici, il n'y a aucun autre changement visible autour du Lac Askja. Des rapports récents confirment des zones hydrothermales autour d'Askja actives. Si l'augmentation de la température du lac Askja est un précurseur à une nouvelle éruption dans le futur proche c'est une spéculation à ce point. [moins]
