Imaging Brine Infiltration and Basal Marine Ice in Larsen C Ice Shelf, Antarctic Peninsula, From Borehole Measurements and Transient Electromagnetics

Killingbeck, Siobhan F. and Kulessa, Bernd and Miles, Katie E. and Hubbard, Bryn and Luckman, Adrian and Thompson, Sarah S. and Jones, Glenn and Galton‐Fenzi, Benjamin K. (2025) Imaging Brine Infiltration and Basal Marine Ice in Larsen C Ice Shelf, Antarctic Peninsula, From Borehole Measurements and Transient Electromagnetics. Geophysical Research Letters, 52 (17): e2025GL115. ISSN 0094-8276

Abstract

Plain Language Summary: We used a novel method to image through the Larsen C Ice Shelf, Antarctica, at a suture zone, where two ice masses merge. We discovered two distinct layers: a 300‐m‐thick upper layer of dense, impermeable ice likely formed from compacted snow, and a thinner layer of porous, frozen seawater. The latter marine ice layer at the base of the ice shelf is less dense than that of a basal marine ice layer observed at a location 195 km downstream. This suggests the basal layer consolidates as it flows toward the ocean. Understanding this layered structure is essential for predicting the ice shelf's stability.