Investigating Near-Thawed Basal Conditions in East Antarctica Using Archival and Modern Ice Penetrating Radar Sounding Data

The George V Land region in East Antarctica could become vulnerable to high rates of mass loss if basal ice within a few degrees of the pressure melting point were to thaw and thereby contribute to rising sea levels. Radargrams have the potential to provide crucial information for distinguishing where the ice-bed interface is near-thawed versus where the bed is already thawed or very frozen. We utilize the Scott Polar Research Intitutes (SPRI) z-scope films and NASAs Operation IceBridge (OIB) datasets which have the potential to provide comparisons between archival and modern observations. To achieve this, the historic SPRI film was examined for radargrams with visible, high-quality bed reflections to enable innovative analysis steps. We focus our analysis on radar flight lines that are upstream or adjacent to coastal regions marked by fast flowing glaciers and covering regions with variation in the basal thermal regime. From these radargrams, we anticipate that near-thawed ice characteristics will be discernible that will provide constraints on the basal thermal state in George V Land and thereby inform future ice sheet modeling objectives.