An increasingly large gash has opened up in northern Russia’s Siberian tundra. During the past few decades, warmer summers and shorter winters have caused permafrost in this region to thaw, which then allows the warmed soils on slopes to slump and erode.

Dozens of the resultant channels and craters are spread across Siberia, but the biggest is Batagaika Crater, about 10 kilometers southeast of the town of Batagay. The Landsat image series shows the initial gash widening from a narrow channel in 1991 to a crater with steep-sided cliffs by 2017, at a resolution of 30 meters. Sentinel-2A’s 10-meter resolution in the natural color bands provides a more detailed look at the crater.

This so-called “megaslump” is being enlarged on a hillslope that leads down to the floodplain of the Batagay River. As the active soil slumps, more of the surrounding and underlying frozen soil is exposed and melts, causing the land to slump further and the extent and speed of the permafrost thawing to increase. Based on satellite image records, the crater is expanding by more than 10 meters per year.

The crater is now about 800 meters wide and up to 86 meters deep. It has exposed older frozen soil horizons that represent a history of environmental changes that span more than 50,000 years. The Landsat and Sentinel missions help track the changes to the crater as scientists study the permafrost and the environmental history now exposed.