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Report on Askja (Iceland) — 27 July-2 August 2022


Askja

Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
27 July-2 August 2022
Managing Editor: Sally Kuhn Sennert

Please cite this report as:

Global Volcanism Program, 2022. Report on Askja (Iceland). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 27 July-2 August 2022. Smithsonian Institution and US Geological Survey.

Weekly Report (27 July-2 August 2022)

Askja

Iceland

65.033°N, 16.783°W; summit elev. 1080 m

All times are local (unless otherwise noted)


On 27 July IMO stated that uplift at Askja began in August 2021 and since then had totaled 35 cm, centered in the W part of Askja lake. The uplift was rapid, compared to similar volcanoes around the world, and likely caused by a magmatic intrusion at an estimated depth of 2 km. Seismicity remained low.

Geological Summary. 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 major rhyolitic explosive eruption from Dyngjufjöll about 10,000 years ago was in part associated with the formation of Askja caldera. Many postglacial eruptions also occurred along the ring-fracture. A major explosive eruption on the SE caldera margin in 1875 was one of Iceland's largest during historical time. It resulted in the formation of a smaller 4.5-km-wide caldera, now filled by Öskjuvatn lake, that truncates the rim of the larger central caldera. The 100-km-long Askja fissure swarm, which includes the Sveinagja graben, is also related to the Askja volcanic system, as are several small shield volcanoes such as Kollatadyngja. Twentieth-century eruptions have produced lava flows from vents located mostly near Öskjuvatn lake.

Source: Icelandic Meteorological Office (IMO)