Geologists at the University of Alaska, Fairbanks, have discovered a lake boiling with methane.
UAF researcher Katey Walter and a National Public Radio crew went to Alaska’s North Slope to record what happens when methane is released as permafrost thaws beneath lakes.
However, upon reaching the destination, the team found the lake violently boiling with escaping methane.
"It was cold, wet and windy. We were dropped off in the middle of nowhere by a helicopter and paddled out to a huge methane plume in the middle of the lake," said Walter, an assistant professor in UAF’s Institute of Northern Engineering and International Arctic Research Center.
"We had no idea what to expect, how strong the bubbling plume would be, whether or not our raft would stay afloat, how dangerous it would be to breath the gas.
"The violent streams of bubbles made the lake appear as if it were boiling, but the water was pretty cold," she said.
Walter, who studies methane emissions from Arctic lakes, especially the connection between thawing permafrost and climate change, said, this summer’s fieldwork indicated that methane hotspots, such as they came across, could come from various sources, not just thawing permafrost.
As permafrost around a lake’s edges thaw, the organic material in it – dead plants and animals – can enter the lake bottom, where bacteria convert it to methane, which bubbles into the atmosphere, sometimes in a spectacular fashion.
"It is unlikely that this methane plume was related to permafrost thaw. It was more likely related to natural gas seepage," said Walter.
"Should large quantities of methane be released from methane hydrates, for instance, in association with permafrost thaw, then we could have large sudden increases in atmospheric methane with potentially large affects on global temperatures," she said.
A story on the field excursion aired on NPR’s afternoon newsmagazine "All Things Considered", on Monday, Sept 10, 2007.
Katey now plans to identify and quantify the sources of the methane hotspots around Alaska. (ANI)