New concerns – Iceland volcano: magma moving towards new volcanic system – could set off another volcano

August 2014 – AFRICA - The magma from Iceland’s Bardarbunga volcano could be moving towards another large volcanic system. Data recorded by a team from the University of Cambridge suggests that 50 million cubic meters of molten rock has moved in the last 24 hours. If it continues on a northern trajectory it could feed into the Askja volcanic system, potentially triggering a large eruption. Prof Bob White said: “It’s headed straight for it.” But he cautioned that volcanoes were hard to predict. “It’s moving at about 4km a day towards Askja, and if it keeps going it will get there in a few days,” he told BBC News. “We know there is a lot of molten rock sitting under the ground beneath Askja, which is a major volcanic system. If this molten rock hits that, we know it is likely to trigger it to erupt. “But who knows, it may just stop. It is still at 5km-depth, and it is possible it could freeze there and not a lot more will happen. That is perfectly plausible.” Over the last 10 days, they have detected large numbers of earthquakes, which have been moving north over a distance of about 40km. They are caused as magma flows beneath the ground, cracking the rocks as it moves.

On Tuesday morning the Bardarbunga volcano was hit by a magnitude 5.7 earthquake, the largest since tremors began in the area last week. The team estimates that about 350 million cubic metres of magma have moved in this period, which is about twice the amount of molten rock that was blasted into the air during Iceland’s Eyjafjallajokull eruption in 2010. Prof Simon Redfern, an earth scientist from the University of Cambridge, said: “It is a huge amount of magma, creating an enormous subterranean channel of molten rock.” He said that the dyke – the underground “plumbing system” that carries the molten rock – could join up with other underground fissures, creating a large network of magma. Prof White added that several scenarios were possible. “One is that it erupts under the glacier,” he said. “That is bad news because this kind of eruption can drive the big ash clouds that can go up 35,000-40,000ft, and that is what happened in 2010 with Eyjafjallajokull.”

However that scenario is looking less likely because the magma is moving beyond the thick ice of the glacier into shallower terrain beyond. If it erupts in this region, with less ice-cover, it could create “fire-fountains” – spectacular plumes of lava, which can be dangerous, but carry less ash. Prof White said: “The third scenario is that it keeps going north, it keeps feeding molten rock and it hits the Askja system and triggers that – then goodness knows what will happen. It could make a lot of disruptive ash all over Iceland.” The last time that the Askja volcano had a major eruption was in 1875. The ash-fall caused crops to fail and killed livestock, triggering a wave of migration away from the north east of Iceland. –BBC