Study reveals greater erosion in areas with discontinuous permafrost

The thawing of permafrost is expected to accelerate in the coming decades, impacting slope stability, channel erosion, sediment mobilization, water quality, and carbon release. However, the relationship between permafrost coverage and erosion intensity at the basin scale is still poorly understood ¹.

Methodology

A recent study used sediments from 12 lakes in Alaska to compare the intensity of erosion on slopes and channels in small basins with different types of permafrost coverage. The researchers analyzed lake sediment cores spanning from the mid-Holocene to the present, combining these data with a Landscape Evolution Model ¹.

The results indicate that diffusive processes, primarily on slopes, are more significant than advective processes, which occur mainly in channels. Furthermore, the average intensity of diffusive processes is approximately 2.1 to 3.0 times greater in areas with discontinuous permafrost compared to areas with continuous permafrost ¹.

The Arctic is warming four times faster than the rest of the planet, and permafrost thawing is one of the most visible consequences. This phenomenon is altering ecosystems, releasing carbon, and threatening indigenous communities in the north. The study highlights that, although continuous and discontinuous permafrost present significant differences, erosion intensity on slopes is greater in areas with discontinuous permafrost ².

The authors of the study warn that the observed differences in intensity may be specific to the locations studied and that additional research is needed to confirm these results in other basins. However, the data suggest that global warming may more than double the intensity of erosive processes in regions with discontinuous permafrost ^1,2.