The Civil Protection Scientific Advisory Board met today to review new data on Bárðarbunga volcano and sent out a press release regarding the meeting. Following is a summary of the findings of a recent scientific expedition on Vatnajökull glacier, which stress the importance of further monitoring.
Echo soundings done June 3-10 revealed no changes in the bedrock topography since last year.
There are no indications either that melt water is accumulating within the caldera. The 65-meter-deep depression in the glacier formed during the events of 2014-2015 has decreased in depth by 8 meters since last year.
Expedition scientists measured gas emissions at ice cauldrons along the caldera rim and found little change in gas emissions since last year’s expedition. The depth and width of the cauldrons has not been measured for quite some time and can only be carried out with airborne surveillance. Therefore, no statement can be made regarding changes in geothermal activity since last year.
A new seismographic station was installed at an elevation of 1600 meters, northwest of the Bárðarbunga caldera on June 5th. The station greatly improves the positional accuracy for earthquake locations underneath the caldera.
Seismographic monitoring shows that accumulated seismic moment magnitude has been increasing from since the middle of September 2015. All in all, 51 earthquakes stronger than magnitude 3 have been registered in Bárðarbunga since the end of the eruption in 2015. Further information about the Bárðarbunga seismicity may be found here.
GPS stations around Bárðarbunga show slow movement away from the caldera.
The most probable explanation for ground deformation and earthquake activity in the area is the inflow of magma at a depth of about 10 to 15 km below Bárðarbunga into the place of origin of the magma which erupted at Holuhraun 2014 to 2015. There are no indications of magma collecting at shallower depths. This process is common in the aftermath of volcanic eruptions.
In the aftermath of the caldera subsidence and following increased geothermal activity, it is probable that meltwater will start collecting under the cauldrons along the caldera rim or within the caldera itself. Therefore, it is imperative to monitor the evolution of the cauldrons, in addition to seismic activity, ground deformation, geothermal activity and gas emissions in Bárðarbunga.