An eruption is predicted to be likely on the Reykjanes peninsula and could happen at any moment. It’s important to assess the hazard level and formulate a potential response.
This was stated by Þorvaldur Þórðarson, a volcanologist with the University of Iceland’s Institute of Earth Sciences, in a lecture given to the Association of Suðurnes Municipalities.
The Mid-Atlantic Ridge—one of the world’s largest divergent tectonic plates—passes through Reykjanes and has seen its fair share of eruptions throughout history, the latest in 1879.
“Then it all began with unrest and an eruption on the Reykjanes Ridge and a few weeks later the Laki eruption started.”
The eruption in the Laki craters, South Iceland, is something that Icelanders will never forget even though it took place over 231 years ago (1783-84).
The infamous eruption lasted eight months and produced over 15 cubic kilometers of lava and around 120 million tons of sulfur dioxide. The eruption brought widespread misery around the northern hemisphere. The mass destruction and geological effects are still felt today.
Through a grant from the European Union, Þórðarson is working on a calculation model based on a database of statistics regarding Iceland’s primary earth hazards. He has been studying the Reykjanes peninsula for the last two years to assess future risk and response.
What Happens in the Event of a Reykjanes Eruption?
“A Reykjanes eruption is usually highly lava-forming, so lava flow is the greatest concern,” said Þórðarson. “Lava flow releases quite a lot of gas, particularly Sulphur, which can spread fast and be a severe detriment to air quality. As we settle more of the peninsula, we need to be aware of points of origin and the ways in which lava can spread.”
Additionally, said Þórðarson, an eruption would affect groundwater reservoirs, causing a potential shortage of drinking water in certain areas, including the capital region.
The research has focused primarily on the westernmost part of the peninsula, where the odds of an eruption are considered greatest.
Plan of Action
“We’ve been looking at volcanic formations, faults, cracks, and geothermal areas, along with tourist and population numbers and infrastructure,” said Þórðarson. “Our long-term prediction indicates that the western part of the peninsula, west of Grindavík, is at the highest risk of eruption.”
If that happens, the people of Grindavík won’t receive much warning: “[They will] get a few hours’ warning, possibly a day if we’re lucky. An eruption starts very quickly and can travel several kilometers within an hour and the speed is so tremendous that you can’t run from it,” said Þórðarson.
“We need to continue assessing the risks and informing the public appropriately when the data is in. When that happens, we’ll be able to define protocols and create a plan of action in the event of a Reykjanes eruption.”
Many areas along the Mid-Atlantic Ridge (MAR) have been surveyed in considerable detail. Surprisingly, the part of the Reykjanes Ridge connecting to Iceland is not one of these areas, although this is arguably the most important part of the ridge system to survey to understand plume-ridge interactions. The position of Iceland over the MAR provides an ideal setting in which to investigate mid-ocean ridge processes and the effects of hot spots on these processes. Iceland is one of only two places on Earth where an oceanic spreading center rises above sea level, which allows nearby work on the submarine ridges to be placed in the extensive geological and geophysical context established for subaerial Iceland. These studies have established the basic pattern of present-day kinematics, geochronology of plate boundary shifts, and geochemical characteristics of the plume, and demonstrate strong plume interaction with the MAR at the Reykjanes Ridge.
(PDF) Reykjanes ridge. Available from: https://www.researchgate.net/publication/246548893_Reykjanes_ridge [accessed Sep 22 2018].