Earth's permafrost starts to squelch

[CVX]

In parts of Fairbanks, Alaska, houses and buildings lean at odd angles.

Some slump as if sliding downhill. Windows and doors inch closer and closer to the ground.

It is an architectural landscape that is becoming more familiar as the world's ice-rich permafrost gives way to thaw.

Water replaces ice and the ground subsides, taking the structures on top along with it.

Alaska is not the only region in a slump. The permafrost melt is accelerating throughout the world's cold regions, scientists reported at the recent Fall Meeting of the American Geophysical Union (AGU) in San Francisco.

In addition to northern Alaska, the permafrost zone includes most other Arctic land, such as northern Canada and much of Siberia, as well as the higher reaches of mountainous regions such as the Alps and Tibet. All report permafrost thaw.

Frederick Nelson, University of Delaware

"It's a very, very widespread problem," said Frederick Nelson, a geographer at the University of Delaware, US.

Scientists attribute the thaw to climate warming. As the air temperature warms, so does the frozen ground beneath it.

Data quest

The observations reiterate the recent findings of the Arctic Climate Impact Assessment report, which attributed the northern polar region's summer sea-ice loss and permafrost thaw to dramatic warming over the past half-century.

Thawing permafrost can cause buildings and roads to droop, and pipelines to crack.

Natural features are also affected. Scientists reported an increased frequency in landslides in the soil-based permafrost of Canada, and an increased instability and slope failures in mountainous regions, such as the Alps, where ice is locked in bedrock.

With the exception of Russia and its long history of permafrost monitoring, global records are insufficient - often too brief or scattered - to determine the precise extent of ice loss, said Dr Nelson.

However, monitoring programmes that are now much larger in scope, such as the Global Terrestrial Network for Permafrost (GTNP), indicate a warming trend throughout the permafrost zone.

Boreholes in Svalbard, Norway, for example, indicate that ground temperatures rose 0.4C over the past decade, four times faster than they did in the previous century, according to Charles Harris, a geologist at the University of Cardiff, UK, and a coordinator of Permafrost and Climate in Europe (Pace), which is contributing data to the GTNP.

"What took a century to be achieved in the 20th Century will be achieved in 25 years in the 21st Century, if this trend continues," he said.

Slip and slide

In Ellesmere Island, Canada, a combination of warmer temperatures and sunny days has triggered an increasing frequency of detachment events, or landslides, over the past 25 years, compared with the previous 75, according to Antoni Lewkowicz, professor of geography at the University of Ottawa.

More: http://news.bbc.co.uk/2/hi/science/nature/4120755.stm

[libertine]

Your information is correct. The pipeline is built above ground on 'stilts'(In some places) to prevent the permafrost from melting a displacing the pipe.

The forest fires in Alaska last summer, which burned millions of acres, burned hot enough to melt many acres of permafrost. It will be an interesting winter for those who try to travel overland on snowmachines this year.

Permafrost is not easy to live with, but living without it is a lot more difficult.

:-2