Globe warming methane bubbling up from undersea reserves

December 21st, 2008 - 2:38 pm ICT by ANI  

National Geographic

Washington, Dec 21 (ANI): A recent expedition by a Russian team has determined that the East Siberian Sea is bubbling with methane, a powerful greenhouse gas, which is being released from underwater reserves. According to a report in National Geographic News, this could be a sign that global warming is thawing underwater permafrost, which is releasing methane that has been locked away for many thousands of years. “If these methane emissions from the Arctic speed up, it could cause really serious climate consequences,” said study leader Igor Semiletov of the Pacific Oceanological Institute in Vladivostok, Russia. Semiletov and colleagues have traveled along the Siberian coast, monitoring methane concentrations in the air and observing the seas. “According to our data, more than 50 percent of the Arctic Siberian shelf is serving as a source of methane to the atmosphere,” Semiletov said. “This vast shelf is about 750,000 square miles (2 million square kilometers)about the same size as Greenland or Mexicoand about 80 percent of it is covered with permafrost,” he added. Permafrost is basically dirt that’’s been permanently frozen for hundreds or thousands of years, much of it since the last ice age. Sea levels back then near the Siberian coast were about 325 feet (100 meters) lower than today, and the exposed ground froze solid down to 1,600 to 2,300 feet (500 to 700 meters) deep. Over the past 10,000 years, sea levels rose to cover some of this permafrost, and in recent years, those seas have seen increases in average temperatures. “As a result, sub-sea permafrost has warmed up to minus 1 degree Celsius (30 degrees Fahrenheit),” Semiletov said. “It’’s very, very close to the thawing point,” he added. Underneath the permafrost are stores of methane, the same as the natural gas people use for cooking and heating. There are also methane hydrates, a solid that forms when methane and water mix in cold temperatures. The hydrates release gas as they warm. “It was assumed that these stores of methane have not been leaking, because the sub-sea permafrost served as a lid keeping hydrates and natural gas in place,” Semiletov said. But now, global warming may be starting to release these stores of methane into the atmosphere. If abrupt methane release became widespread, it could create a feedback loop that would lead to even more drastic global warming. “With this newly obtained data, we suggest an increase of methane release from the East Siberian Arctic shelf,” Semiletov said. “We have obtained a drastic increase of air methane in some sitessometimes up to four times higher than the background (global average),” he further added. (ANI)

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