The fissure eruption in Holuhraun lava, north of Vatnajökull glacier, which started at midnight, is already over. The eruption lasted for about three or four hours, according to Páll Einarsson, professor geophysics at the University of Iceland.
"It was a small eruption and a small sample of the magma that is moving underground reached the surface," says Páll, describing the events of the night as an abberation in the larger course of events of the last two weeks.
Páll agrees with fellow professor of geophysics, Magnús Tumi Guðmundsson, who earlier today described the eruption as an "accident". "The magma intrusion strayed unnecessarily close to the surface and some magma came out," Páll says.
The Icelandic Met Office has downgraded the aviation alert over the volcanic eruption area from red to orange. There is not considered to be a risk of volcanic ash reaching the atmosphere.
The Icelandic Transport Authority has also reduced the restricted flight area around the volcanic activity from 10 nautical miles (NM) to 3 NM and 5,000 foot altitude. The warning area restricting instrument flight rules flight remains unchanged.
The eruption fissure is about 5 kilometers from the Vatnajökull glacier. The fissure appears to be about 1 kilometer long. The lava is thin and flowing quickly southeast towards the glacier.