Detecting and Mapping Abrupt Landscape Change in Permafrost Regions of Siberia

Abstract:

The Arctic is warming two times faster than any other place in the world. With this comes the thawing of permafrost, which can alter the landscape, particularly in areas with high ground ice content where thaw-driven ground collapse is becoming more common. The Yamal and Gydan Peninsulas in Western Siberia are in a region that is undergoing rapid change, including the occurrence of retrogressive thaw slumps (RTS) and novel processes such as the formation of gas emission craters (GEC). These features can rapidly displace hundreds of cubic meters of ground material, posing a threat to human infrastructure and to the people who live in the Arctic. Further, biogeochemical transformation of thawed permafrost substrate can render GECs and RTSs sources of greenhouse gasses to the atmosphere. However, the full implications of these features are uncertain, in part, because of a lack of information about their distribution in remote locations of the Arctic. To understand these features better we used freely-available remotely sensed products of surface reflectance (Landsat) and elevation (ArcticDEM) and Google Earth Engine to detect and map landscape change across a 327,000 km2 region in the Yamal and Gydan Peninsulas in Western Siberia. We found that 5.09% of the landscape displayed change, with retrogressive thaw slumps making up one of the most common observed landscape changes. We found that of the disturbed areas that were validated with high resolution imagery 53% were retrogressive thaw slumps. We also detected several lakes that had characteristics of gas emission craters; however, ongoing work is needed to confirm these findings. Given the rapid pace of change in the Arctic, much of which is not easily accessible on the ground, this satellite-based approach provides new insight into the frequency of abrupt events that are occurring across the landscape and that can have global impacts.