Meeting of the Civil Protection and Emergency Management´s Science Board 5th of March

5. mars 2021 18:00

Science Board March 5

News release:

The Civil Protection and Emergency Management’s Science Board held an online meeting today to discuss the earthquake swarm in the Reykjanes Peninsula. The meeting was attended by representatives of the Icelandic Met Office, the University of Iceland, the Environment Agency of Iceland, Reykjavik Energy, Kaust University, Uppsala University, the Directorate of Health, the Epidemiologist, Isavia-ANS, HS-Orka and ÍSOR.

Measuring and data received in the last 24 hours was reviewed.

As per an announcement from the Science Board yesterday, it is the scientists’ assessment that the latest data does not indicate magma moving rapidly closer to the surface. While this situation lasts the likelihood of an eruption is not high, but a possible rapid change in the status must be assumed.

It is the joint opinion of the Science Board that if it comes to an eruption, all available data indicates that it will be in the area between Fagradalsfjall and Keilir. This is in line with the scenarios already published in the Science Board’s announcements. The effect of the tensity from the area of unrest between Fagradalsfjall and Keilir most likely explains the earthquakes that have occurred in Svartsengi and near Trölladyngja in the past few days, as no deformation has been detected that can be linked to magma on the way to the surface. There is therefore no reason to expect an imminent eruption in these locations at this time and not in any other location in the Reykjanes Peninsula outside of the area of unrest by Fagradalsfjall and Keilir.

Further about the activity and processing of latest data

Eartquake activity and magma movements continue. The strongest quake activity after midnight is confined to Fagradalsfjall and has moved slightly NE with view of activity yesterday. Model calculation shows that quake activity west of Fagradalsfjall and by Þorbjörn is due to changes in tensity which the magma path causes in a large area all around. Activity by Trölladyngja is also linked to changes in tensity from the magma path.

No unrest like the one detected approximately 48 hours ago has been measured since. That unrest indicated that magma was moving in the area where the strongest quake activity has occurred. This is probably a so-called magma path forming, which can possibly break through, all the way to the surface.

Further interpretation of the satellite images received yesterday will be reviewed, as well as the latest GPS measuring, which will show continued displacement in the area. A few models based on the satellite images and the latest GPS measuring were created, in order to understand better the extent and location of the magma path. The magma path lies almost vertically in the earth’s crust. The biggest opening of the earth’s crust is there underneath and reaches the depth of approximately 5 km. With view of the model calculation results, it is considered most reliable to assume that if it comes to an eruption, a crack could open somewhere in the area that has recently been most active, from the centre of Fagradalsfjall to Keilir.

Models indicate that this would be a medium-size eruption of approximately 0.3 km3, which is of comparable dimensions as Arnarseturshraun in the Reykjanes Peninsula. Such an eruption would most likely not threaten population.  

The magma path lies at a very shallow level in the earth’s crust. The likeliest models indicate that the path is 5-6 km long and that a 1.5-2 km distance could be down to its upper layer. A good reason is therefore to respond when volcanic unrest is detected like the other day, which can be indications of the beginning of an eruption.

The likeliest scenarios:                                  

  • Earthquake activity will decrease in the next few days or weeks.
  • The swarm will increase with stronger quakes up to 6 in magnitude in the vicinity of Fagradalsfjall.
  • A quake of 6.5 in magnitude will occur, originating in Brennisteinsfjöll.
  • Magma intrusion continues in the vicinity of Fagradalsfjall:
    • Magma intrusion activity decreases and magma solidifies
    • Leads to effusive eruption with lava flow which will probably not threaten population

The status of the set-up of new measuring equipment was also reviewed. The specialists from the Icelandic Met Office, the University and other collaborators have worked hard in the last few days on adding to measuring equipment in the area to be able to give a clearer view of developments of the chain of events in the Reykjanes Peninsula. GPS recording stations have already been added during the week and the set-up of more such stations will continue during the weekend as well as the set-up of seismographs. All the measuring equipment will then be connected to the Icelandic Met Office’s monitoring system.

The Science Board will meet again briefly tomorrow to discuss the latest data and measuring.