For years scientist have known permafrost can act as reliable gauge to chart climate change in the north. A new study in the journal Nature Geoscience reveals the wide extent and speed in which ice wedges are degrading and altering the landscape.
For years Anna Liljedahl and her colleagues have been charting changes in ice wedges that can form characteristic polygon shapes in the arctic landscape. Liljedahl is assistant professor at the University of Alaska Fairbanks’ Water and Environmental Research Center. While previous studies have documented permafrost thawing. Their research encompassed the circumpolar region with sites in Russian, Canada and Alaska. And it showed a consistent thawing taking place.
“The process is happening not just in Alaska, but often Canadian and Russian Arctic,” Liljedahl said. “And it is happening in a relatively short time period, less than a decade, even after one very warm summer.”
Liljedahl says as the structure of polygon ice wedges degrade, new channels for water are formed, ultimately draining and drying the landscape. The implications are varied, she says. In the summer of 2007 the Alaska arctic saw scant rainfall. That summer also saw large tundra fires. Liljedahl says such dynamics can create their own feedback loops.
“We could have potentially normal rainfall in the summer but this is still creating a really dry surface and that could have an easier time for the fires to get started, said Liljedahl. “That, in turn, can then degrade the ice wedges even more.”
Liljedahl says as the arctic landscape drains, more sediments and nutrients can flow downstream changing other ecosystems. Offering other opportunities for further research.