Alabama-Sized Area Of Canada's Permafrost Melting Rapidly, Portending Rapid Carbon Release
Huge slabs of Arctic permafrost in northwest Canada are slumping and disintegrating, sending large amounts of carbon-rich mud and silt into streams and rivers. A new study that analyzed nearly a half-million square miles in northwest Canada found that this permafrost decay is affecting 52,000 square miles of that vast stretch of earth—an expanse the size of Alabama.
According to researchers with the Northwest Territories Geological Survey, the permafrost collapse is intensifying and causing landslides into rivers and lakes that can choke off life downstream, all the way to where the rivers discharge into the Pacific Ocean. Similar large-scale landscape changes are evident across the Arctic including in Alaska, Siberia and Scandinavia, the researchers wrote in a paper published in the journal Geology in early February. The study didn't address the issue of greenhouse gas releases from thawing permafrost. But its findings could help quantify the immense global scale of the thawing, which will contribute to more accurate estimates of carbon emissions.
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The new study was aimed at measuring the geographical scope of thawing permafrost in northwest Canada. Using satellite images and other data, the team studied the edge of the former Laurentide Ice Sheet, a vast expanse of ice that covered two-thirds of North America during the last ice age. The disintegration of the permafrost was visible in 40- to 60-mile wide swaths of terrain, showing that, "extensive landscapes remain poised for major climate-driven change." "Things have really taken off. Climate warming is now making that happen. It's exactly what we should expect with climate change," said Steven V. Kokelj, lead scientist on the Canadian mapping project. "And the maps that we produced clearly indicated it's not just a random pattern. We're sort of connecting dots here for the scientific community."
Other global evidence of similar large-scale permafrost changes have recently been documented in Siberia, where scientists with the Permafrost Laboratory at the University of Sussex (UK) are monitoring another rapidly growing scar in the earth. More than a half-mile of once-frozen ground has collapsed 280-feet deep, according to their study published in in the journal Quaternary Research in February. The researchers said they expect to see the rolling tundra landscape transform, including the formation of large new valleys and lakes.
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https://insideclimatenews.org/news/27022017/global-warming-permafrost-study-melt-canada-siberia