Detailed Seismic Bathymetry Beneath Ekström Ice Shelf, Antarctica

Implications for Glacial History and Ice-Ocean Interaction

authored by

Emma C. Smith, Tore Hattermann, Gerhard Kuhn, Christoph Gaedicke, Sophie Berger, Reinhard Drews, Todd A. Ehlers, Dieter Franke, Rapahel Gromig, Coen Hofstede, Astrid Lambrecht, Andreas Läufer, Christoph Mayer, Ralf Tiedemann, Frank Wilhelms, Olaf Eisen

Abstract

The shape of ice shelf cavities are a major source of uncertainty in understanding ice-ocean interactions. This limits assessments of the response of the Antarctic ice sheets to climate change. Here we use vibroseis seismic reflection surveys to map the bathymetry beneath the Ekström Ice Shelf, Dronning Maud Land. The new bathymetry reveals an inland-sloping trough, reaching depths of 1,100 m below sea level, near the current grounding line, which we attribute to erosion by palaeo-ice streams. The trough does not cross-cut the outer parts of the continental shelf. Conductivity-temperature-depth profiles within the ice shelf cavity reveal the presence of cold water at shallower depths and tidal mixing at the ice shelf margins. It is unknown if warm water can access the trough. The new bathymetry is thought to be representative of many ice shelves in Dronning Maud Land, which together regulate the ice loss from a substantial area of East Antarctica.

External Organisation(s)

Alfred Wegener Institute (AWI) Helmholtz Centre for Polar and Marine Research
Norwegian Polar Institute
Federal Institute for Geosciences and Natural Resources (BGR)
University of Tübingen
University of Cologne
Walther-Meißner-Institute for Low Temperature Research
University of Bremen
University of Göttingen

Type

Article

Journal

Geophysical research letters

Volume

47

ISSN

0094-8276

Publication date

28.05.2020

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Geophysics, General Earth and Planetary Sciences

Sustainable Development Goals

SDG 13 - Climate Action, SDG 14 - Life Below Water

Electronic version(s)

https://doi.org/10.1029/2019GL086187 (Access: Open)