Notes from the meeting of the Civil Protection Scientific Advisory Board 11. September

Scientists from the Icelandic Met Office and the Institute of Earth Sciences and representatives of the Civil Protection in Iceland attend the meetings of the Scientific Advisory Board of the Icelandic Civil Protection. Representative from The Environment Agency of Iceland and the Chief Epidemiologist and the Directorate of Health, were also present.

Conclusions of the Scientific Advisory Board of the Icelandic Civil Protection:
The eruptive activity at Holuhraun continues at similar intensity. Lava flows at similar rates as yesterday. The lava is flowing towards East but widens slightly towards North. The main flow follows the river bed of Jökulsá á Fjöllum. No explosive activity due to the lava and river water interaction has been observed, but steam rises from the lava.

Air quality in urban areas in the East of Iceland:

Forecasts indicate that high concentrations of sulphuric gases may be expected in the northern part of the Eastern fjords, Fljótsdalur, Hérað, Jökuldalur, and Vopnafjörður. High concentrations could occur in other areas as well. People who feel discomfort are advised to stay indoors, close the windows and turn off air conditioning. Measurements of air quality can be found on the webpage The Meteorological Office issues warnings if conditions change to the worse.

Instructions from the office of the Chief Epidemiologist and The Environmental Agency can be found on their web-sites.

Air quality at the eruption site:

Gas emissions at the eruption site remain high. As local gas concentrations at the site can be life threatening, people at the eruption site should wear gas masks and gas meters. At the eruption site, local wind anomalies can occur due to thermal convection from the hot lava. This makes the conditions on site extremely dangerous as winds can change suddenly and unpredictably

Earthquake activity in the caldera of Bárðarbunga remains similar to that of the last days. Epicenters are distributed along the northern and south-eastern caldera fault. An earthquake of M 5.3 occurred at 00:07 h. Earthquake activity at the dyke tip has decreased. More than 30 events have been detected since midnight. Low frequency tremor is similar to what has been observed in the last few days.

GPS observations show insignificant crustal movements supporting the assumption that the amount of magma flowing into the dyke continues to be similar to the magma erupted to the surface. Considering the time period since the beginning of the eruption slight movements towards the Bárðarbunga caldera indicate continuing subsidence of the caldera.

Three scenarios are considered most likely:

  • Subsidence of the Bárðarbunga caldera stops and the eruption on Holuhraun declines gradually.
  • Large-scale subsidence of the caldera occurs, prolonging or strengthening the eruption on Holuhraun. In this situation, it is likely that the eruptive fissure would lengthen southwards under Dyngjujökull, resulting in a jökulhlaup and an ash-producing eruption. It is also possible that eruptive fissures could develop in another location under the glacier.
  • Large-scale subsidence of the caldera occurs, causing an eruption at the edge of the caldera. Such an eruption would melt large quantities of ice, leading to a major jökulhlaup.

Other scenarios cannot be excluded.

From the Icelandic Met Office:

The Aviation Colour Code for Bárðarbunga remains at ‘orange’ but the code for Askja has been changed to ‘green’.