Canadian Permafrost Melting Rapidly

Series of Palsas near Canada's James Bay

These small mounds are in an accelerating state of decay around Canada's James Bay due to melting of the permafrost beneath them.

The permafrost around Canada’s James Bay is retreating northward as the frozen ground responds to a warming climate, Canadian researchers say.

Simon Thibault and Serge Payette say they found that the southern edge of permafrost moved northward about 80 miles over the past 50 years.

Writing in the journal Permafrost and Periglacial Processes, the pair says the trend was uncovered by comparing current aerial observations with photos taken from 1957.

Small, lichen-covered mounds that form naturally over frozen peat bogs have disappeared as the permanently frozen ground beneath them has thawed, Payette said.

These palsas have nearly disappeared or are in an advanced state of deterioration over the entire James Bay area, the team concludes.

They say the lack of long-term climate observations in the affected area make it impossible to directly confirm the melt is due to climate change.

But Thibault and Payette say they believe it is the likely cause.

Photo: File