We use ICESat-2 laser altimetry crossovers and repeat tracks collected over the North Slope of Alaska to estimate elevation changes due to the deformation of seasonally freezing and thawing permafrost. We compare these measurements with a time series of surface deformation from Sentinel-1 interferometric synthetic aperture radar (InSAR) and demonstrate agreement between these independent observations of surface deformation. Both methods resolve pronounced surface subsidence during the 2019 thaw season within the 2007 Anaktuvuk River fire scar. A temporal relationship between measured surface subsidence/uplift and changes in normalized annual degree days is observed, consistent with the thermodynamically driven seasonal freezing and thawing of the active layer. We discuss optimal strategies of post-processing ICESat-2 data for permafrost applications, as well as the future potential of joint ICESat-2 and InSAR investigations of permafrost surface dynamics.
