Over five hundred earthquakes since midnight

According to an announcement from the Civil Protection in Iceland, over five hundred earthquakes have been detected arround Bárðarbunga since midnight. Seismic activity has decreased somewhat since the eruption started early on sunday morning, yet still remains high.

At 08:58 UTC today, a magnitude 5.0 earthquake was recorded on the Bárðarbunga caldera, and another of magnitude 5.2 at 11:41 UTC in the same region.

The lava eruption on Holuhraun continues and at 20:00 UTC yesterday, the lava extended over a 3-km-area. This corresponds to a magma discharge of 300 to 500 cubic metres per second. From observations yesterday evening, the volume of erupted lava is between 16 and 25 million cubic metres.

Gas and steam rises to a couple of hundred metres above the eruption site, extending up to 1,200 m downwind.

The eruption has not created any ash-fall.

Gas measurements indicate a high level of sulphur dioxide. People could be exposed to highly dangerous gas levels close to the eruption. It is essential that those visiting the eruption site are equipped with gas sensors and gas masks.

According to the latest GPS observations, horizontal ground movements continue in response to the dyke intrusion. There is no clear sign of a pressure decrease in the dyke intrusion in connection with the ongoing eruption, although there are irregularities in GPS displacements at nearby stations. The northern extent of the dyke intrusion has not changed to any great extent.

Four scenarios most likely

It remains unclear how the situation will develop but four scenarios are considered most likely.

The migration of magma could stop, resulting in a gradual reduction in seismic activity and no further eruptions.

The dike could reach the Earth’s surface causing another eruption, possibly on a new fissure. Lava flow and (or) explosive activity cannot be excluded.

The intrusion reaches the surface and another eruption occurs where either the fissure is partly or entirely beneath Dyngjujökull. This would most likely produce a flood in Jökulsá á Fjöllum and perhaps explosive, ash-producing activity.

An eruption in Bárðarbunga. The eruption could cause an outburst flood and possibly an explosive, ash-producing activity. In the event of a subglacial eruption, it is most likely that flooding would affect Jökulsá á Fjöllum. However it is not possible to exclude the following flood paths: Skjálfandafljót, Kaldakvísl, Skaftá and Grímsvötn.

Other scenarios cannot be excluded.