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

Ricarda Dziadek,Karsten Gohl,Fausto Ferraccioli

doi:10.1038/s43247-021-00242-3

Abstract

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.

Highlights

Geothermal heat flow in the polar regions plays a crucial role in understanding ice-sheet dynamics and predictions of sea level rise
We examine the distribution of geothermal heat flow (GHF) as a key factor to reveal past and present geodynamic, tectonic, and lithospheric processes and their correlation to the presently observed enormous ice mass loss in this region
The Amundsen Sea Embayment is underlain by the eastern branches of the West Antarctic Rift System, which extends from the Ross Sea to the Amundsen Sea and Bellingshausen Sea sectors of West Antarctica[9,10,11]

Summary

Introduction

Geothermal heat flow in the polar regions plays a crucial role in understanding ice-sheet dynamics and predictions of sea level rise. The Curie depth is considered as a proxy for geothermal heat flow, because it represents the depthto-bottom of a magnetic source in a first approximation of the temperature dependence of magnetization in crustal rocks (details are in Supplementary Method 1.1 to 1.3).

Results

Conclusion