The volcanic activity in Bárðarbunga caldera and the neighboring area has already produced two eruptions. First, the so-called phony eruption occurred on Saturday one week ago, August 23. That eruption appeared on earthquake meters, but was not visible, because it did not reach through the ice cap on the glacier. It should be kept in mind that the ice is between 400 and 600 meters thick.
Scientists called that eruption off when they saw no sign of it on the surface, but now they say it was real but stopped after a short while.
The second eruption lasted for less than four hours in Holuhraun lava, to the north of the glacier. It began after midnight on August 29 and stopped shortly after that.
Professor Magnús Tumi Guðmundsson told RÚV this morning that the first eruption was ten times more powerful than the second one. To understand how much power is needed to melt the icecap it should be kept in mind that the power of all the nuclear bombs in the world would only melt one percent of the Vatnajökull glacier ice, according to scientist Oddur Sigurðsson.
According to Magnús Tumi, an eruption in Bárðarbunga is possible.History shows that a subglacial eruption in more common than one in the neighboring area. Then again, there might be no more eruptions.
If an eruption starts below the icecap, that can, and probably will, cause a flood in one of the glacial rivers, most likely Jökulsá á Fjöllum. If it goes through the ice then ash might stream up. That happened in an eruption in 1717 when a big eruption took place.
Now scientists are waiting for the results of an analysis of the Holuhraun lava. “That should give us the fingerprints of the material, whether it is typical Bárðarbunga stuff or somehow different and more complicated,” Magnús Tumi concluded.