The scientists who flew over Vatnajökull glacier this morning now state that the cauldrons first observed as circular depressions on the surface yesterday total three and not four, as earlier reported, and are 5-km (3-mile) long combined, ruv.is reported shortly before 3 pm.
The icecap is 400-600-m (1,300-2,000-feet) thick where the cauldrons formed. They are believed to have been caused by melting at the bottom of the glacier and to be located above the watershed of Jökulsá á Fjöllum, a glacier river that flows through Northeast Iceland.
As earlier reported, scientists have concluded that the water level in glacial lakes Grímsvötn has heightened by 5-10 meters (16-33 feet) in the past days, which equals an addition of 10-30 million cubic meters (350-1,100 cubic feet) of water.
The melt water from the cauldrons could have flowed either to Jökulsá á Fjöllum or Grímsvötn. There are no changes to the conductivity in Jökulsá á Fjöllum.
However, slightly increased conductivity has been detected in river Kaldakvísl in Northeast Iceland, which flows from Köldukvíslarlón lagoon by Vatnajökull through Hágöngulón lagoon. There are no changes to the water level in Hágöngulón.
The district commissioner in Húsavík has called inhabitants in the vicinity of glacial river Skjálfandafljót in Þingeyjarsýsla, Northeast Iceland, to a civil meeting in local community center Ljósvetningabúð at 8 pm tonight to discuss possible evacuation, ruv.is reports.
Skjálfandafljót, which flows through Bárðardalur valley where a number of farms are located, also originates in Vatnajökull. However, no changes have been detected in the water flow.
Seismic activity is similar in nature as in the past days. Three larger earthquakes hit Bárðarbunga around midnight and this morning, 4.0 and 5.0 in magnitude.
Seismic activity increased slightly in Askja volcano around 8 am this morning. It’s believed that changes in tension due to divergence caused by the intrusive dike extending northwards from Bárðarbunga through Dyngjujökull outlet glacier are having an effect in the Askja area.
The dike has lengthened by 1-1.5 km since yesterday, to a lesser extent than in the past days, and now reaches the Askja fissure swarm. GPS sensors indicate that this is having a significant impact on the area. However, nothing has been reported on possible scenarios.