Monitoring Mount Oræfajokull
Iceland’s position on the Mid Atlantic Ridge makes it a hot spot for tectonic activity. Regular earthquakes and volcanic activity are part of what makes Iceland’s landscape so unique. However the Icelandic people must remain vigilant and observant of the many volcanoes across the island to make sure they remain prepared to manage these natural hazards.
We asked earth scientist, author, explorer and a member Icelandic parliament, Ari Trausti Guðmundsson to provide us with the latest update from monitoring Mount Oræfajokull.
Can your students identify the various ways Oræfajokull is being monitored?
Follow up discussion for your classroom:
- Think about management of hazards, tourism opportunities and the local economy…
- Can you name some benefits and disadvantages of living in this tectonic area?
“Oræfajokull, Iceland´s largest central volcano (2,110 m), has appeared in the media recently. Earthquakes, including deep source shocks, and sudden geothermal activity have caused some interest.
Airborne surveillance has revealed a circular cauldron in the centre of the snow and ice field that covers the 500-600m deep and 5km wide top caldera. The circular cauldron was about 1,000m wide and 20-25m deep in late November, caused by melting at the bottom of the glacier.
Increased discharge in a river that flows from a long valley glacier in the south slopes of the mountain (Kvíarjokull glacier and river Kvia) contains chemical elements that confirm new and strong geothermal activity.
This fact and the sudden increase in seismic activity may suggest magma up-flow into the roots of the volcano.
This notion is supported by GPS-data, indicating a small magma intrusion. By mid-December, surveillance revealed the ice cauldron depth to be 40-50m and the circular rim crevasses to be wider still.
The process may come to a halt but it could also be a prelude to a volcanic eruption, large or small, within weeks, months or years.
Subglacial eruptions produce ash due to the contact between magma and water, and result in a flash flood (jokulhlaup). When looking at the risk of flooding caused by an eruption we also take into account the height of the mountain and the power of the eruption.
We know that Oræfajokull erupted with great force in 1362 after a long repose (10 cubic km of airborne tephra). The volcano erupted again in 1727-8 with moderate force.
No one can precisely predict the development of the events but there has been increased monitoring on the volcano. In order to be prepared, an evacuation plan and other counter-measures are being addressed in cooperation with local authorities.”