Iceland volcano continues to rumble, still threat of eruption

WATCH ABOVE: Authorities in Iceland are warning the airline industry about a possible volcanic eruption that could send ash spewing into the sky – and into the path of planes. CBS’ Alphonso Van Marsh reports from London.

TORONTO – Though seismic activity beneath Iceland’s Bardarbunga Volcano has quieted somewhat, the government has evacuated tourists from nearby towns.

Since Aug. 16 more than 3,000 earthquakes have been rocking the small northern island. These earthquakes – called a swarm – prompted experts to issue an alert about the possible eruption of the volcano.

READ MORE: Iceland closes roads as it raises alert for possible volcanic eruption

Iceland, just 103,000 square km – slightly smaller than Newfoundland – is home to 30 active volcanoes. Bardarbunga, a stratovolcano about 2000 metres in height, lies in the volcano “hot spot” on the island, beneath the Vatnajokull Glacier. The volcano has had about 100 mapped eruptions, though it’s likely that there have been more, the last in 1910.

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The reason for Iceland’s volcanic activity is due to the fact that it lies on a spreading plate boundary, where Earth’s crust moves apart. As this happens new material surfaces and essentially creates new crust.

Rikke Pedersen, Manager of the Nordic Volcanological Center at the University of Iceland said that at the moment the material is spreading beneath the surface, laterally rather than upwards.

Iceland’s plate boundaries
Iceland’s plate boundaries.

“If it keeps at subsurface, I’d say there’s no threat,” Pedersen said of the current situation.

“The question is, if it starts propagating towards the surface, it will of course result in an eruption beneath the ice sheet, which causes massive melting.”

And that’s the problem: the glacier’s thickness is between 400 to 600 metres. If an eruption of ash were to take place, it would create flooding in the rivers that drain from the glacier.

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Because of that potential danger, the area north of the Vatnajokull Glacier has been closed, and tourists have been evacuated. It’s not that an eruption is imminent, it’s just as a precaution as it takes some time to evacuate sparsely populated areas.

But for residents, it’s just part of living in Iceland.

“Icelanders are used to the volcanoes just being a part of life,” Pedersen said.

“It’s not really that people here are very afraid. They sort of just look at it as sort of an excitement. The civil protection agency is very skilled at dealing with these kinds of situations and people completely trust them.”

As for ash and the threat to aviation, it would take as long as 24 hours for the ash to melt its way through the ice. If that happened, ash particles would be ejected into the air causing headaches for airlines crossing the Atlantic.

But there’s good news: The ash particles of Bardarbunga aren’t as fine as those from the eruption of Eyjafjallajokull in 2010, which disrupted air travel across Europe for more than a month. Eyjafjallajokull’s eruption disrupted about 100,000 flights, affected more than 10 million passengers and cost the airline industry roughly $1.8 billion in lost revenue.

WATCH: Iceland Volcano Ash Plumes over Europe from Eyjafjallajokull
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“The most likely scenario is that it will not cause as big a threat to the aircraft,” Pedersen said. “Of course it depends a lot on the weather at the day of the eruption, so of course it is still difficult to predict.”

Pedersen believes it’s likely that an eruption won’t happen, though there are no guarantees. Statistically, when these types of seismic swarms occur, the eruption takes place within a couple of days. But it’s been almost five days.

“The likelihood is decreasing, but of course the threat is still there.”

One of the more threatening volcanoes in Iceland is Katla, a large volcano just east of Eyjafjallajokull. It has a history of erupting about twice every 100 years. Its last eruption was in 1913.

For Pedersen, Bardarbunga presents an opportunity to learn more about volcanoes.

“It forms the basis of research, so of course, this is a very interesting time,” she said. “It’s very interesting to follow.”