Archives de mots clés: eruption

Soon sweaters knitted with volcanic wool

A fascinating phenomenon known as Pele´s hair can be seen blowing away from the eruption site at Dyngjusandur. It was also seen in the Laki eruption in 1783.

“It was noticed blowing all around the fissure, but no one could explain or understand why. It looks like tufts of hair and feels like glass wool. At first people thought this was vegetation that had been affected by the eruption somehow, but there’s no plant life in sight. It can’t be sheep wool either because there are no sheep,” says journalist Kristján Már Unnarsson, who has been reporting from the scene since the eruption started.

“Then someone remembered the old texts about the Laki eruption from 230 years ago. The texts mentioned something similar, and it is believed to be the oldest known reference to the phenomenon. Turns out that it’s neither flora or fauna, but a mineral by-product of the eruption.”

In Icelandic it’s called Witch´s hair while the international name refers to Pele, the Hawaiian volcano god.

“It feels like a lock of hair when you hold it, but it’s actually rock. It’s glass that’s cooled down as the magma erupts from the fissure. The gas pressure is so great that it blows the magma into thin strands, almost like hair. Then it falls to the ground and starts blowing along and bundles up,” says volcanologist Þorvaldur Þórðarsson.

Winter arrives at Holuhraun

Snow drifting over new lava at Holuhraun. (Picture: Kerstin Langenberger/Instit. of Earth Sciences)

A month has now passed since the Holuhraun lava eruption began. Winter has now arrived in the Icelandic highland, putting the new lava in stark contrast. The effusive eruption is becoming one the largest in Iceland in recent decades; only the Hekla eruption 1947-48 produced more lava.

According to estimates made two days ago, the new lava field has reached 44 square kilometers and its volume was belived to be at least 0.6 cubic kilometers. The eruption has been relatively steady from the beginning and show no signs of being in decline.

The Holuhraun eruption is now among the largest one in Iceland for the last 150 years. According to geophysicist Magnus Tumi Gudmundsson at the Univ. of Iceland´s Institute of Earth Sciences, only the Hekla eruption in 1947-48 produced more lava, during the 13 month eruption. That created 0.8 cubic kilometers of lava; should the Holuhraun eruption continue with the same intensity as before, that milestone could be reached in about 2 weeks.

Seismic activity in Bardarbunga caldera continues at a similar rate as previous days, according to a status report published this morning, and GPS measurements show continuing slow movements. “Six earthquakes bigger then M3,0 were recorded since noon yesterday. The biggest one was M5,2 at 12:34 yesterday. Smaller earthquakes were detected in north part of the dyke and around the eruption site.”

ruv.is/volcano

bjornm@ruv.is

This story, by the Icelandic National Broadcasting Service (RUV), was updated on 29 September 2014, at 12.00 GMT

Snow drifting over new lava at Holuhraun. (Picture: Kerstin Langenberger/Instit. of Earth Sciences)