Alaska Lake Boiling With Methane

Alaska Lake Boiling With Methane



2007 September -   Last month, University of 
Alaska-Fairbanks researcher Katey Walter brought a National Public Radio 
crew to Alaska's North Slope to show them how methane is released when 
permafrost thaws beneath lakes.
 
When they reached their destination, Walter and the crew found a 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 with 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," said Walter, an assistant professor in UAF's Institute 
of Northern Engineering and International Arctic Research Center. 
"The violent streams of bubbles made the lake appear as if it were 
boiling, but the water was pretty cold," she said. 

Walter studies methane emissions from arctic lakes, especially the 
connection between thawing permafrost and climate change. 
As permafrost around a lake's edges thaws, 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. 
Methane is a one of the six greenhouse gases governed by the Kyoto 
Protocol. Methane is over 20 times more effective in trapping heat in the 
atmosphere than carbon dioxide. It remains in the atmosphere for between 
nine and 15 years. 

Walter said this summer's fieldwork indicates that methane hotspots can 
come from various sources, not just thawing permafrost. 
Methane is emitted from a variety of human sources such as landfills, 
natural gas and petroleum systems, agricultural activities, coal mining, 
stationary and mobile combustion, wastewater treatment, and certain 
industrial processes. Methane is also a primary constituent of natural gas 
and can be captured from landfills or other sources and burned to produce 
energy. 

Walter's next goal is to identify and quantify the sources of the methane 
hotspots around Alaska. 
"It is unlikely that this methane plume was related to permafrost thaw," 
said Walter, adding that the methane boiling out of the lake was more 
likely related to natural gas seepage. 
"Should large quantities of methane be released from methane hydrates, for 
instance, in association with permafrost thaw," she said, "then we could 
have large sudden increases in atmospheric methane with potentially large 
affects on global temperatures." 
Walter's project is one of many at the university being conducted as part 
of the International Polar Year, an international event that is focusing 
research efforts and public attention on the Earth's polar regions. 

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