– Volcanic eruption begins under Iceland’s (and Europe’s) largest glacier (Ice Age Now, Aug 23, 2014):
Dyngjujokull eruption begins – It’s all subglacial for now
Iceland’s Dyngjujokull volcano began erupting today, prompting the country to raise its aviation alert level to red, the country’s Meteorological Office said. However, the eruption is still just considered a minor event at this point
Dyngjujokull volcano is not far from Bárðarbunga, which gave us the largest eruption of the Holocene (this era).
An alert level of red — the highest level — indicates the threat of “significant emission of ash into the atmosphere.” Meanwhile, the National Commissioner of the Icelandic Police has raised the alert phase to emergency phase.
Seismic data indicates that hot magma is melting the ice beneath the Dyngjujokull icecap on the Vatnajokull glacier, said Met Office vulcanologist Melissa Pfeffer.
She said it could take up to a day for the ice — which is 330 to 1,300 feet (100 to 400 m) thick — to melt. Or, it’s also possible that the eruption might remain contained beneath the glacier.
If the eruption does melt through the ice, the amount of ash produced depends on the thickness of the ice, Pfeffer explained.
“The thicker the ice, the more water there is, the more explosive it will be and the more ash-rich the eruption will be,” she said.
Vatnajokull glacier, which lies 200 miles (320 km) east of the capital of Reykjavik, is not only the largest glacier in Iceland, it is the largest glacier in Europe.
A 2010 eruption of Iceland’s Eyjafjallajokul volcano produced an ash cloud that forced cancellation of more than 100,000 flights and stranded millions.
The largest eruption of the Holocene (this era) was at the Bardarbunga volcano caldera.”
“Observations are now showing the beginning of deflation in the caldera,” says reader Beano. “There is a 25 kilometer dyke (or trench) under the ice where magma is flowing.” (I don’t know where Beano got this info.)
“Deflation is not a good thing – let’s hope it stabilizes,” says Beano. “The last thing that the planet need would be a caldera collapse with all that ice on top.”
“The resulting phreatic explosion and then eruption would be catastrophic. You would hear the bang both in the lower 48 and Europe.
“If reports are issued of rapidly continuing Bardarbunga volcano caldera deflation be prepared to start to hold goodbye parties.
“Another reminder. The largest eruption of the Holocene (this era) was at the Bardarbunga volcano caldera.”
(Confirmed: According to volcanodiscovery.com, “approximately 8600 years ago, Bárðarbunga produced the largest known lava flow during the past 10,000 years on earth (more than 21 cubic kilometers of volume.”)
Thanks to Beano, Marque, Ron de Haan, David Wigtil, Joe Banks, Argiris Diamantis and Tom O’Hara for these links
“They also said that glacier-coated volcanoes tend to erupt more violently due to the ice and with more ash,” says Marque.