Schrödinger’s Volcano

On August 16, the Western media spotlight fell on Iceland once again. As is usually the case when the outside world likes to acknowledge our existence, an eruption was involved. Or was there?

That day it became known that there had been a slow and steady build-up of unusually strong seismic activity at Bárðarbunga, Vatnajökull Glacier’s highest peak. All signs indicated that a subglacial volcano was about to erupt.

International headlines ranged from modest “Bardarbunga eruption sparks red travel alert,” to the slightly more worrying “Eruption May Cause Monumental Flood,” to the cataclysmic “Icelandic volcano could trigger Britain’s coldest winter EVER this year.” Airlines around the world went on high alert—Air Berlin went so far as to cancel a flight to Iceland, lest their plane become stranded. Plans changed. On Monday, Icelandic hardcore band Icarus’ European tour was promptly cancelled by their Swedish booking agency…

The ground kept shaking and up to a thousand earthquakes went off in the area each day, with some reaching five on the Richter scale. This indicates that the magma underneath is expanding in new directions, ten kilometres beneath the surface, with an estimated millions of cubic metres added to the underground dike daily.

The area north of Bárðarbunga was evacuated, PM Sigmundur Davíð Gunnlausson sat in crisis meetings with the meteorological office, academics, rescue and civil defence forces, and pretty much everyone prepared for the worst. The world watched in anticipation.

Midday the following Saturday, scientists from the Icelandic Meteorological Office announced that a small subglacial eruption had commenced Northeast of Bárðarbunga. The aviation code was escalated to “red,” and the area a no-fly zone.

Another Icelandic volcano had gone off.

Jumping the gun

Later that same afternoon, geophysicist Magnús Tumi Guðmundsson announced that earlier reports might have been premature—an airplane survey had not revealed an increased melting of the ice, which is one of the principal indicators of an active subglacial eruption. The earthquakes had been out in force, magma was detected underground, and the other signs were all present—still, the magma appeared not to have broken through to the surface.

The state of emergency was eventually called off, threat levels downgraded from “red” to “orange,” and even the click-baitiest of headlines became more subdued. Local farmers, such as Gunnar Björnsson from Sandfell in Öxarfjörður, criticised authorities for having gone too far with their evacuations, but Magnús Tumi maintained that it is always better to err on the side of caution where eruptions are concerned.

After a period of calm, the earthquakes resumed, reaching a record high 5.7 on the Richter scale on August 26. The Icelandic Civil Protection Scientific Advisory Board forecast three possible scenarios given the known facts:

“The migration of magma could stop, attended by a gradual reduction in seismic activity.”

“The dike could reach the surface of the crust, starting an eruption. In this scenario, it is most likely that the eruption would be near the northern tip of the dike. This would most likely produce an effusive lava eruption with limited explosive, ash-producing activity.”

“An alternate scenario would be the dike reaching the surface where a significant part, or all, of the fissure is beneath the glacier. This would most likely produce a flood in Jökulsá á Fjöllum and perhaps explosive, ash-producing activity.”

As we sent this issue off to print, increased seismic activity in and around Bárðarbunga, as well as the Askja caldera, had prompted authorities to call an urgent meeting to assess the situation.

There was no eruption.

Yet.

—

Update: Mere hours after the Grapevine went to print, there was a small eruption at Holuhraun.

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