Scientists call the events permafrost detachment slides. Instead of thawing from the top down, these landslides seem to originate from a weakened base

November 13, 2026 11:33 a.m.

A scar left by the 2018 Redstone River permafrost landslide, one of the two events investigated in the new study. Adapted from J. M. Young et al., Geophysical Research Letters , 2026

In 2017 and 2018, a pair of strange landslides moved huge masses of rock and dirt in Canada’s Northwest Territories. The events occurred in the central Mackenzie Valley, and one of them even dammed a river and created a lake .

The two natural disasters are part of a new class of landslides scientists are calling “permafrost detachment slides” in a study published in the journal Geophysical Research Letters in September. They may have been partially triggered by severe wildfires that occurred in 1995, which destabilized the ground and allowed the base of the permafrost to thaw.…