Interior Alaska and Siberia Permafrost Thawing Together
Permafrost, the frozen ground that provides a solid foundation for much of the world's northern regions, is not what it used to be. In many areas of both interior Alaska and Siberia, permafrost has warmed to within one degree Celsius of thawing. A researcher who compared permafrost in both areas said widespread permafrost thawing could change much of the northern landscape in the first few decades of the 2000s.
Vladimir Romanovsky studies permafrost at the Geophysical Institute of the University of Alaska Fairbanks. At a recent meeting of the American Geophysical Union in San Francisco, Romanovsky unveiled a permafrost record of Siberia along a 1,200-mile transect and compared it to a network in Alaska. Permafrost warming in the two areas was quite similar. In Fairbanks and the eastern Siberia city of Yakutsk, for example, permafrost has warmed about 1.5 degrees C during the past 30 years.
An increase in temperature of less than two degrees might not seem like much, but that warming has much of the permafrost in both areas barely cold enough to remain solid. Looking at computer models that predict at least a 2.5-degree C increase in average air temperature during the next 50 years, Romanovsky said interior Alaska and Siberia are probably both in for a major change. Sinking buildings, roller-coaster roads, and boreal forest changing to wetlands could be realities of the near future if current warming persists. "Thawing permafrost will bring lots of problems," he said.
Using a computer model to see how permafrost might react based on past and present changes, Romanovsky predicted that permafrost in the Interior of Alaska will probably begin to thaw over vast areas as early as 2015. After a possible cooling period, major thawing will most likely occur by 2040, he said. He said this major thawing should affect areas that are currently stable, such as the Goldstream Valley outside Fairbanks and others mall valleys.
Computer models aside, Romanovsky presented some solid facts about permafrost, such as measurements from Barrow and Tiksi, a town in northern Siberia. In Barrow, permafrost temperatures had been dropping recently, but in the last two years permafrost temperatures were the highest researchers had measured since they were first taken in 1923. Tiksi showed a similar pattern.
At Ivotuk, on the upper Colville River on Alaska's North Slope, Romanovsky was surprised to find permafrost at -2 degrees C. That area of Alaska has historically featured much colder permafrost. "The temperature there should be about minus 5," Romanovsky said.
Permafrost lies beneath about 80 percent of Alaska, and a higher percentage of Siberia. For years, builders have kept permafrost frozen by raising houses off the ground to keep warmth from seeping into the ground and melting permafrost. Engineers have also designed systems that keep the soil frozen beneath roads and pipelines with heat exchangers, but if the climate continues to warm, people may be forced to refrigerate the soil to keep it frozen, as Alyeska Pipeline Service Company currently does for the pipeline in an area south of the Alaska Range.
Thawing permafrost may be the most noticed sign of a warming climate in Alaska, especially in the Interior, where many people live, work and drive over frozen soil without realizing it.
