August 21, 2014

expert reaction to seismic activity in Bárðarbunga volcano

Further expert reaction to the detection of seismic activity in Bárðarbunga, a large sub-glacial volcano in Iceland.

Update from Dr Nicolas Bellouin:

“The travel disruption in Northern Europe caused by the eruption of Eyjafjallajökull in 2010 was caused because winds carried a plume of volcanic ash across European flight paths and over major airports, including Heathrow and Gatwick.

“If the Bardarbunga volcano erupts, throwing massive amounts of volcanic ash into the atmosphere, we will be at the mercy of the wind. The effect on the UK will depend very much on which way the wind is blowing.

“The current cold snap many of us are experiencing in the UK is due to the fact that at the moment the wind is coming from the north – putting Britain directly in the firing line of any volcanic eruption from Iceland, if it happens in the next few days.

“However, the latest forecast indicates that from Sunday, the wind direction will change, bring winds from the west. This means a plume of dust from any volcanic eruption in Iceland would most likely be pushed east, over northern parts of Scandinavia and into Russia, and not into UK airspace.

“Of course, no-one knows for certain if and when this volcano is going to erupt. When it does, we do know that the UK is much better prepared now to monitor and predict where the plume is going to go, thanks to the collaborative efforts of scientists here in the UK and in Iceland. This should help aviation authorities to minimise any travel disruption that might ensue.”

Prof David Rothery, Professor of Planetary Geosciences at the Open University, said:

“The earthquake locations under the ice at Bardarbunga migrated northeastwards overnight. It is possible that a fissure eruption will begin either below the ice or perhaps beyond the edge of the icecap. Any eruption is not likely to produce a high ash column, because Icelandic magma does not usually contain enough gas to drive a powerful explosive jet. But until erupted samples are available for analysis we can’t rule out the possibility that magma has been stored and fractionated long enough to become gas-rich, as was the case in the 2010 eruption of Eyjafjallajokull. Meltwater from the icecap could also mix with the magma to cause explosions.

“If any eruption does produce a high column of fine ash, it would be a significant problem for UK and trans-Atlantic air traffic only if the wind carried it southeast, which today’s winds would actually do. However, whereas in 2010 aviation protocol was not to fly through air where ANY ash was present, the rules have been changed to allow flying though ash provided that it does not exceed 4 microgrammes per cubic metre. It is challenging to measure ash density with high confidence, but even so a repeat of the 2010 Eyjafjallajokull today would lead to a smaller volume of airspace being closed to traffic.

“The most likely hazard if an eruption occurs is flooding when subglacial meltwater escapes, and the Icelandic authorities have already closed access to vulnerable areas.

“If a fissure eruption occurs beyond the icecap, it could be very impressive – perhaps a 100 metre high fire-fountain along a 1 km fissure, feeding lava flows. I am looking forward to seeing video if this happens.”

Declared interests

None declared