The most rapidly changing parts of the Antarctic Ice Sheet have been observed in Amundsen Sea Sector/Bellingshausen Sector of West Antarctica. Various processes contribute to the (in)stability of the ice sheet here. For instance, inflow of modified, warmer Circumpolar Deep Water, geothermal heat from the underlying crust and the crusts flexural response to unloading of the ice mass. Our objective is the investigation of geothermal heat flow in this sector, which is poorly constrained, albeit providing a crucial boundary condition for ice sheet models and related sea level rise predictions. We discuss airborne, high-resolution magnetic anomaly data from the Amundsen Sea Sector, to provide additional insight into deeper crustal structures related to the West Antarctic Rift System in the Amundsen/Bellingshausen sector. With the depth-to-the-bottom of the magnetic source (DBMS) estimates, we reveal spatial changes at the bottom of the igneous crust and the thickness of the magnetic layer that can be further incorporated into tectonic interpretations and serves as a proxy for geothermal heat flow estimates. The DBMS results and further available datasets (e.g. crustal thickness) are synthesized in high-resolution, thermal 2D models of the crust in two representative profiles along Pine Island and Thwaites Glacier. Because crustal parameters, such as radiogenic heat production, thermal conductivity, crustal thickness and Moho temperatures yield large uncertainties, we test the models under variations of these parameters. Our models reveal elevated heat flow distributions ranging between 50 mW/m² and 100 mW/m² and further advance the understanding of the thermal crustal state in this sector.