Arctic Shelf Releases More Methane Than Previously Thought
Recent studies led by University of Alaska Fairbanks scientists show that the East Siberian Arctic Shelf is not as impermeable as once believed. It is instead leaking the large amounts of methane gas (30 times more potent than carbon dioxide) it stores.
This is particularly concerning because, unlike many other deposits, it exists in shallow waters. When methane is released at deeper levels of the ocean it has time to oxidize and convert to carbon dioxide before reaching the surface. Methane from the East Siberian Arctic Shelf has no time for this process. As a result, research shows that the Shelf is emitting 7 teragrams of methane in to the atmosphere (about 1.1 million tons) annually. This number is equal to the amount of methane released from the rest of the ocean. And while the levels of methane are typically 8 to 10 percent higher in the Arctic compared to the rest of the world, data shows the levels in the air above the Shelf to be another 5 to 10 percent higher than that.
It is difficult to project the effects of this release, the scientists admit, but the warming globe only hastens the process. Throughout history there have been times when the Shelf existed above sea level, frozen and impermeable. But as sea levels rise and the East Siberian Arctic Shelf is submerged, the 12 to 15 degree increase in temperature accelerates its melting.
