The volume of magma which has surfaced in the volcanic eruption in Holuhraun is five to six times greater than what surfaced during the eruption in Eyjafjallajökull in 2010 and four times greater than in the 2011 Grímsvötn eruption. In both eruptions, primarily ash was emitted.
The Holuhraun is massive compared to other eruptions in Iceland too. In the two months that it has lasted, the volume of lava has reached 1 cubic km, or 1,000 million cubic meters, which is more lava than was erupted during the 13 months that the 1947 Hekla eruption lasted, ruv.is reports.
In terms of volume of lava, the Holuhraun eruption is now the biggest in Iceland since the 1783 Laki eruption (aka Skaftáreldar). The lava which surfaced during that disastrous eruption is 14 times the volume of the Holuhraun eruption.
“It now covers an area the size of Reykjavík and in some places it is 10-20 meters thick,” geophysicist Magnús Tumi Guðmundsson, who is on the Civil Protection Department’s Scientific Advisory Board, said of the new lava in Holuhraun.
The Holuhraun eruption began in the northeastern highlands on August 29. It was preceded by intensified seismic activity in Bárðarbunga volcano, under Vatnajökull glacier, starting on August 16.
The Bárðarbunga caldera has been in constant subsidence, which now measures 40 meters, since. The area of the icecap which has subsided is over 70 square kilometers in size.
A sub-glacial eruption is still a possible future scenario and scientists remain on the alert.