Vladimir Romanovsky walks through the dense black spruce forest with ease. Not once does he stop or slow down to balance himself on the cushy moss beneath his feet insulating the permafrost.
It’s a warm day in July, and the scientist is looking for a box that he and his team have installed on the ground. It’s hidden nearly six miles (10km) north of the Geophysical Institute at the University of Alaska in Fairbanks, where he’s a professor of geophysics and heads the Permafrost Laboratory.
The box, which is covered by tree branches, contains a data collector connected to a thermometer installed below ground for measuring permafrost temperature at different depths. Permafrost is any earth material that remains at or below 0C (32F) for at least two consecutive years.
Romanovsky connects his laptop to the data collector to transfer the temperature data for this location – called Goldstream III – which he will later add to an online databaseaccessible to both scientists and interested individuals.
“Permafrost is defined on the basis of temperature, the parameter that characterises its stability,” Romanovsky says.
The thaw is deepening and expanding, causing the permafrost underneath to become less stable
When the temperature of permafrost is below 0C (32F), for example -6C (21F), it is considered stable and will take a long time to thaw or to change. If it's close to 0C, however, it's considered vulnerable.
Every summer the portion of soil overlaying the permafrost, called the active layer, thaws, before refreezing the following winter. At Goldstream III, on this July day, the summer thaw currently ends at 50cm depth.
As the Earth warms and summer temperatures climb, the thaw is deepening and expanding, causing the permafrost underneath to become less stable.
The consequences, if this thawing continues, will be profound, for Alaska – and for the world. Nearly 90% of the state is covered in permafrost, which means entire villages will need to be relocated, as the foundations of buildings and roads crumble. And if this frozen cache releases the millennia of accumulated carbon it has locked within, it could accelerate the warming of our planet – far beyond our ability to control it.
A vulnerable state
As permafrost thaws, houses, roads, airports and other infrastructure built on the frozen ground can crack and even collapse.
“We are seeing some increased maintenance on existing roads over permafrost,” says Jeff Currey, materials engineer for Northern Region of the Alaska Department of Transportation Public Facilities. “One of our maintenance superintendents recently told me his folks are having to patch settling areas on the highways he's responsible for more frequently than they were 10 or 20 years ago.”
Similarly, infrastructure built underground – such as those for utilities – is suffering as temperatures rise.
“In Point Lay – on the coast in northwest Alaska – for instance, they're having all sorts of trouble with their water and sewer lines buried in permafrost soil,” says William Schnabel, director of the Water & Environmental Research Center at the University of Alaska Fairbanks. “The permafrost soil has thawed and we get water and line breaks because the ground shifts.”
The concern is even more pronounced for those living in rural areas who don't have enough funds to combat the effects of thawing permafrost. For those residents it's not just about collapsing buildings, which is common now, but also water supply.
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