7% Of Alaskan Interior Permafrost Already Showing Signs Of Melting

[hatrack]

When a person searches the word "Alaska" in the computer abstracts for the recent fall meeting of the American Geophysical Union in San Francisco, that person gets 265 hits. Many scientists are studying Alaska. Here's what some are finding:

• About 47 percent of ground underlying the Interior -- the land between the Alaska Range and the Brooks Range -- has permafrost beneath it, according to a survey done by Torre Jorgenson of Alaska Biological Research Inc. and Tom George of Terra-Terpret. In a Cessna 185, George flew at 5,000 feet above ground level east to west over the Interior and took digital photographs that Jorgenson analyzed for terrain features that suggested permafrost. In a preliminary count, Jorgenson also calculated that 7 percent of the Interior showed signs of thawed permafrost. In those areas, he saw evidence of thermokarst -- collapsed ground often filled with water or covered with mats of floating vegetation.

EDIT

Two lakes in the Yukon might tell scientists something about the Northland's distant past. Lesleigh Anderson of the U.S. Geological Survey in Denver has paddled an inflatable boat on hundreds of Yukon territory lakes, pulling cores of sediment from the lake bottoms. She is focusing on two aquamarine lakes in the Yukon, one that gets flushed with fresh water and another that's a closed system, gaining water through snowmelt and rainfall and losing it only to evaporation. Anderson is looking at oxygen-isotope ratios in the sediment to determine changes in rain, snow and evaporation during the past 7,500 years. Those ratios tell her something about the strength of the Aleutian Low, an Alaska weather-maker that affects the entire Pacific Northwest. The lakes show how the Aleutian Low likely changed how wet and dry the Yukon has been.

"It's dryer now in the Interior than it has been in the past 5,000 years," she said. Anderson has started coring similar lakes in northwest Colorado in hopes of finding weather patterns there that affect much of Colorado's water supply -- the snow that falls in the Rocky Mountains.

EDIT

http://www.adn.com/life/story/7326191p-7238247c.html

[Dogmudgeon]

1. How fast is this permafrost melting happening?

This will be a major concern, since the area will become increasingly hospitable for microorganisms -- which will produce copious amounts of carbon dioxide and methane.

If I'm not mistaken, the area has seen a major increase in carbon gasses since around 2000. Similar changes have been observed in northern Russia and Siberia.

--p!

[Systematic Chaos]

2. Can you say "feedback loop"?

It's gonna be quick and very, VERY painful, I'm afraid. :(