One month ago, I wrote about a dramatic landscape feature in western Alaska called the Selawik Slump. The slump, caused by thawing permafrost, looks like a bomb crater leaking mud from the boreal forest into a clear northern river. There are dozens of them in northern Alaska, though none as big as the one on the Selawik River.

There are also many of these beacons of change in the Yukon Territory, according to Doug Davidge of Whitehorse, who read the Selawik column in the Yukon News. A few years ago Davidge was flying over the Peel River country east of Eagle Plains for work when he saw a gaping wound on a hillside. Scientists once described these features as “tundra mudflows.” They now call them retrogressive thaw slumps.


“We flew over some very dramatic looking retrogressive thaws, and we could pick out other ones as we flew along,” he said.

Though it’s not part of Davidge’s job for Environment Canada, the giant scar on the landscape intrigued him enough to send him to Google Earth on his own time to search for more of the characteristic scoops missing from hillsides along the remote Peel River drainage. He found a lot of them.

“I don’t have the total count in front of me,” he said from his office in Whitehorse. “I keep adding them to the list, but it’s probably in the range of 200 or so ... There are many other huge ones out there.