High geothermal heat flow beneath Thwaites Glacier in West Antarctica inferred from aeromagnetic data

The Amundsen Sea sector, Antarctica, is underlain by shallow Curie depths - where the magnetic properties of rocks change - according to airborne magnetic data. This suggests high geothermal heat flow in this region of the West Antarctic Rift System. Geothermal heat flow in the polar regions plays a crucial role in understanding ice-sheet dynamics and predictions of sea level rise. Continental-scale indirect estimates often have a low spatial resolution and yield largest discrepancies in West Antarctica. Here we analyse geophysical data to estimate geothermal heat flow in the Amundsen Sea Sector of West Antarctica. With Curie depth analysis based on a new magnetic anomaly grid compilation, we reveal variations in lithospheric thermal gradients. We show that the rapidly retreating Thwaites and Pope glaciers in particular are underlain by areas of largely elevated geothermal heat flow, which relates to the tectonic and magmatic history of the West Antarctic Rift System in this region. Our results imply that the behavior of this vulnerable sector of the West Antarctic Ice Sheet is strongly coupled to the dynamics of the underlying lithosphere.

Automated summary

The Amundsen Sea sector of Antarctica has shallow Curie depths, indicating high geothermal heat flow. By analyzing geophysical data, variations in lithospheric thermal gradients were revealed, showing that areas under rapidly retreating glaciers have elevated geothermal heat flow due to the tectonic and magmatic history of the region. This suggests that the behavior of the West Antarctic Ice Sheet in this vulnerable sector is closely linked to the dynamics of the underlying lithosphere.