Characterizing Deformation and Ridging in Shorefast Ice using Remote Sensing Techniques
Abstract
Sea ice ridges are an important morphological feature that stabilize shorefast ice across the Northern Alaskan coastline. This stability is important to local communities and ecosystems that rely on this habitat for food security and safety. Investigating the development of shorefast ice around Utqiagvik, AK, we describe an approach to identify grounded ridges throughout the winter season. To do this, we utilize high resolution altimetry data from NASA’s ICESat-2 satellite which provides unprecedented along-track detail that allows, for the first time, the detection of individual pressure ridges. We apply the University of Maryland Ridge Detection Algorithm (Duncan and Farrell, 2022) using ICESat-2 elevation data to identify and calculate ridge sail heights along each satellite track. From these heights, we estimate the depth of the ridge using sail/keel height ratios described in the literature. The calculated ridge depths are compared with high-resolution bathymetric data (NCEI Digital Elevation Model Mosaic) to classify potentially grounded ridges. This methodology for identifying and quantifying grounded ridges in shorefast ice will improve our understanding of coastal ice processes in a changing environment.