Glaciers and Permafrost

The Globe and Mail featured a piece today entitled "Melting glaciers unearth new challenges Roads, buildings, rail lines and airports will cost more to replace as their foundations turn into sludge." When reading the title, I automatically knew that it was wrong: melting glaciers do not threaten infrastructure, but melting permafrost does. The first section of the article talks exclusively about glaciers and how they are retreating. It is only halfway down the first page of the online article that we get to the real problem:

According to a recent University of Alaska study, climate change could add as much as $6-billion to what is now expected to be the $40-billion cost of building and maintaining public infrastructure in Alaska between now and 2030.

Alaska's roads, buildings, railroads and airports are all going to cost more to replace in part because the foundation upon which they are built is turning into sludge. That once permanently frozen subsoil - permafrost - is thawing.

"This is a huge issue for the state," said Peter Larsen, co-author of the report by the Institute of Social and Economic Research. "Canadians should be interested in this issue as well because a place like the Yukon faces the same challenges.

"What is going to happen to the permafrost when temperatures go above freezing? The airport in Nome is having a severe problem with thawing permafrost, and there are people from the state's Department of Transportation on the ground there trying to deal with the fact that the runway is facing a serious problem."

Melting permafrost usually turns into mud. This poses two main threats to construction: building that are built upon a solid foundation of permafrost will start to sink into the mud should the permafrost melt. If a slope has a high ice content in the permafrost, then you risk having a mudslide if the slope melts. This, of course, will endanger anything built on the slope or below the slope.

The Globe and Mail article is clearly more infatuated with glaciers than permafrost. Glaciers are somewhat sexier than permafrost when describing the dangers of global warming. It is a shame as permafrost is a fascinating thing.

In the countries that have permafrost, it is necessary to deal with permafrost to build any structure. In the Russian Far East, massive apartment building 10 or more stories high were built on pilings driven deep down into the permafrost. Space was left between the building and the soil to allow air to circulate and to dissipate heat generated by the building and its inhabitants away from the soil so the permafrost would not melt. Without this, all these building would have tilted, reminiscent of the Leaning Tower of Pisa before collapsing.

The building of roads is particularly challenging. The tires rolling on the pavement generate heat, a byproduct of friction. Without friction, there would be no traction, and cars and trucks would not move. The heat generated by the cars and trucks eventually melts the permafrost and can create massive sinkholes below the pavement. The only way of avoiding this is by insulating the permafrost from the pavement to ensure that the permafrost does not melt.

The natural environment is of course shaped by the permafrost. Amazing natural structures can emerge in the landscape: hills of pure ice that push upwards out of the ground. These are not glaciers, rather, they are features of the permafrost itself.

Permafrost is central to life in the Far North and are as interesting as glaciers in my opinion.