Climate change, post-harvest losses threatening food production in North – Jigawa Govt

A groundbreaking study published in Geophysical Research Letters has revealed an unprecedented phenomenon in northern latitudes - a new type of landslide triggered by climate change. These massive landslides, known as permafrost detachment slides, were observed in areas with relatively thin permafrost and could potentially impact a wider region as the planet continues to warm.

The research, led by Joseph Young from the University of Alberta, discovered these slides in Canada's Northwest Territories, where they had not been observed before. Young likened the occurrence of these landslides to a "switch" flipping in the region's stability, stating that the permafrost system had been stable for over 10,000 years, and then suddenly changed.

During field observations, the researchers noticed large scar marks in valleys that had previously hosted stable permafrost. Utilizing satellite imagery and fieldwork, they determined that these landslides were not caused by typical melting permafrost. Instead, they found blocks of frozen material embedded in the debris, some as tall as a two-story house (33 feet or 10 meters).

To understand the mechanics behind these slides, the researchers employed an electrical current to measure the depth of permafrost on the slopes. They focused on two significant slides: one in the Johnson River Valley (2017) and another in the Redstone River Valley (2018). The Johnson River slide moved more than 636 million cubic feet (18 million cubic meters) of soil and rock, while the Redstone River slide displaced nearly 159 million cubic feet (4.5 million cubic meters) of debris.

The researchers built a model to explain how these icy landslides occurred. They found that the warming permafrost, combined with severe wildfires in the area (such as one in 1995), created cracks near the top of the slopes. These cracks allowed thawing to penetrate deeper, eventually melting the bottom layer of permafrost. This process took about 20 years to reach a depth of 66 feet (20 meters), as observed in both the Johnson and Redstone River valleys.

Although these landslides have not yet damaged any infrastructure in Canada's Northwest Territories, they have created new lakes by damming rivers and rapidly releasing sediment downstream. The researchers warn that other areas in Canada and Alaska with permafrost depths ranging from 66 to 130 feet (20 to 40 meters) are also vulnerable to similar slides, especially considering the increasing intensity of wildfires in northern latitudes.