Vast methane 'plumes' seen in Arctic ocean as sea ice retreats

http://www.independent.co.uk/news/science/vast-methane-plumes-seen-in-arctic-ocean-as-sea-ice-retreats-6276278.html

Steve Connor
Dec. 13, 2011

Dramatic and unprecedented plumes of methane - a greenhouse gas 20 times more potent than carbon dioxide - have been seen bubbling to the surface of the Arctic Ocean by scientists undertaking an extensive survey of the region.

The scale and volume of the methane release has astonished the head of the Russian research team who has been surveying the seabed of the East Siberian Arctic Shelf off northern Russia for nearly 20 years.

In an exclusive interview with The Independent, Igor Semiletov of the International Arctic Research Centre at the University of Alaska Fairbanks, who led the 8th joint US-Russia cruise of the East Siberian Arctic seas, said that he has never before witnessed the scale and force of the methane being released from beneath the Arctic seabed.

"Earlier we found torch-like structures like this but they were only tens of metres in diameter. This is the first time that we've found continuous, powerful and impressive seeping structures more than 1,000 metres in diameter. It's amazing," Dr Semiletov said.

"I was most impressed by the shear scale and the high density of the plumes. Over a relatively small area we found more than 100, but over a wider area there should be thousands of them," he said.

Scientists estimate that there are hundreds of millions of tons of methane gas locked away beneath the Arctic permafrost, which extends from the mainland into the seabed of the relatively shallow sea of the East Siberian Arctic Shelf.

One of the greatest fears is that with the disappearance of the Arctic sea ice in summer, and rapidly rising temperatures across the entire Arctic region, which are already melting the Siberian permafrost, the trapped methane could be suddenly released into the atmosphere leading to rapid and severe climate change.

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