Climate Change Drives Widespread and Rapid Thermokarst Development in Very Cold Permafrost in the Canadian High Arctic

Abstract Climate warming in regions of ice-rich permafrost can result in widespread thermokarst development, which reconfigures the landscape and damages infrastructure. We present multisite time series observations which couple ground temperature measurements with thermokarst development in a region of very cold permafrost. In the Canadian High Arctic between 2003 and 2016, a series of anomalously warm summers caused mean thawing indices to be 150?240% above the 1979?2000 normal resulting in up to 90 cm of subsidence over the 12-year observation period. Our data illustrate that despite low mean annual ground temperatures, very cold permafrost (