The intrusive dike formed by magma flowing out of the Bárðarbunga caldera keeps extending to the north and has now reached the fissure swarm of the Askja volcanic system, according to Kristín Vogfjörð, director for research at the Iceland Met Office.
“Seismic activity has increased in Askja and the tension there has increased because of the dike. It has now reached the Askja fissure swarm. For that reason we have upgraded the alert level for air traffic to yellow. It means that there isn’t any danger but that we’re monitoring the developments. We still don’t know what this might lead to,” Kristín told ruv.is.
The fractions and depression in Holuhraun lava field on top of the dike north of Dyngjujökull, an outlet glacier on the northern border of Vatnajökull, were caused by the magma that flows through the dike, Kristín stated.
Kristín added that the cauldrons observed on Vatnajökull glacier yesterday are being examined more closely. “We are measuring the depth of the cracks. It must be clear in order for us to determine how much water has flooded. It has most likely flowed to Grímsvötn because there are no changes to Jökulsá á Fjöllum.”
Kristín explained that the water level in Grímsvötn, glacial lakes on Vatnajökull, has increased by 5-10 meters (16-33 feet) in the past days. “It could also have been caused by increased melting of the icecap [because of warm weather]. We don’t know for sure.”
Director of the Department of Civil Protection and Emergency Management Víðir Reynisson stated that no changes have been made to the contingency plan, although a meeting is scheduled with the inhabitants of Þingeyjarsveit in Northeast Iceland in local community center Ljósvetningabúð tonight.
“We’re not concerned because of floods from Grímsvötn. We know them well, especially from the 1996 Gjálp eruption, and know the signs of a flood starting from there,” Víðir concluded.
If the melt water is flowing into Grímsvötn, there will likely be a glacial flood to the south of Vatnajökull, instead of in glacial river Jökulsá á Fjöllum to the north of the glacier.