Antarctic geothermal heat flow and its implications for tectonics and ice sheets

Geothermal heat flow (GHF) is an elusive physical property, yet it can reveal past and present plate tectonic processes. In Antarctica, GHF has further consequences in predicting the response of ice sheets to climate change. In this Review, we discuss variations in Antarctic GHF models based on geophysical methods and draw insights into tectonics and GHF model usage for ice sheet modelling. The inferred GHF at continental scale for West Antarctica (up to 119 mW m⁻², 95th percentile) points to numerous contributing influences, including non-steady state neotectonic processes. Combined influences cause especially high values in the vicinity of the Thwaites Glacier, a location critical for the accurate prediction of accelerated loss of Antarctic ice mass. The inferred variations across East Antarctica are more subtle (up to 66 mW m⁻², 95th percentile), where slightly elevated values in some locations correspond to the influence of thinned lithosphere and tectonic units with concentrations of heat-producing elements. Fine-scale anomalies owing to heat-producing elements and horizontal components of heat flow are important for regional modelling. GHF maps comprising central values with these fine-scale anomalies captured within uncertainty bounds can thus enable improved ensemble-based ice sheet model predictions of Antarctic ice loss.