Bárðarbunga Activity Raises Questions

The Bárðarbunga caldera has sunk by 15 metres, which does not mean an eruption is on the way, but is the deepest recorded caldera sink in over a century. Meanwhile, the flowing lava from Holuhraun is approaching the river Jökulsá á Fjöllum.

RÚV reports that a supervisory plane, flying over the area last Friday, detected that the caldera of the Bárðarbunga volcano has sunk by about 15 metres. Magnús Tumi Guðmundsson, a professor of geology at the University of Iceland, believes this is due to repeated and powerful seismic activity in the area.

“We see no signs of an eruption or increasing temperatures in the caldera,” he told reporters. “We can say that this does not reduce the chances that there will be an eruption, in the caldera or in Bárðarbunga itself.”

The last time a caldera sink was measured at an equal or greater depth was in 1875, when Öskjuvötn was created. At that time, the caldera sink was measured at about 300 metres.

Meanwhile, Vísir reports, lava continues to flow out of the Holuhraun eruption, at a rate of about 40 to 50 metres per hour. At the time of this writing, the lava is predicted to reach the Jökulsá á Fjöllum river in about 16 hours.

“What we can expect to happen is when the lava reaches the river, we can expect a steam explosion that will have a localised effect on the area,” Programme Director of the Icelandic Met Office Kristín Jónsdóttir told reporters. “Of course, we could also see the lava reach the river and have a localised effect on that, but we don’t expect the effect to be great.”