Bardarbunga volcano - Now more likely if erupts, will be partly on land, not under glacier.

Bardarbunga volcano - Now more likely if erupts, will be partly on land, not under glacier
(volcanodiscovery).

The seismic crisis in Bárðarbunga and Dyngjujökull continues strongly. Today alone, more than 400 quakes of magnitudes up to 4 were detected, mostly at the N end of the active intrusion that has been going on.

The location of the quakes indicating the front of the magma intrusion (dyke) continues to advance northwards. Its tip is now outside the glacier and approaching the Askja caldera. In case of an eruption, it is now more likely that at least some of it occurs on land (and not under the glacier).

In total, the intrusion has a length of approx. 40 km. Horizontal displacement in the crust, based on GPS data, approaches 1 meter above the dyke. A rough estimation of the volume of intruded magma is about 1 cubic kilometers.

The likelihood of a large (or even very large) rifting fissure eruption is becoming greater each day. This would occur as soon as the underground intrusions "open the lip" of the fissures on the ground and let magma to rise and decompress, producing violent lava fountaining eruptions.

The Bárdarbunga volcanic system is one of the most active and productive in the world and has been the site of Iceland's largest historic eruption in 1477.

Judging from current and historic data, and given that , one of the most likely scenarios at the moment would be an event similar to the fissure eruption of the so-called "Krafla Fires" at the Krafla volcano's fissure swarm during 1980-84.

Even a really large event such as the 1783 Skaftár Fires (Laki eruption) cannot be ruled out (but for now has only a small chance of happening).

In the meantime, Icelandic authorities have downgraded the emergency status of the area, although road closings and restrictions north of Vatnajokull are still in effect.

Over 700 earthquakes were detected from midnight to noon Monday. Several earthquakes were above 3.0 magnitude.

Suggested further reading: Bárðarbunga – Nature of the beast (VolcanoCafe)