Subglacial hydrological control on flow of an Antarctic Peninsula palaeo-ice stream

• Main Authors: Larter, RD, Hogan, KA, Hillenbrand, CD, Smith, JA, Batchelor, CL, Cartigny, M, Tate, AJ, Kirkham, JD, Roseby, ZA, Kuhn, G, Graham, AGC, Dowdeswell, JA
• Format: Article in Journal/Newspaper
• Language: English
• Published: EGU 2019
• Subjects: 37 Earth Sciences; 3709 Physical Geography and Environmental Geoscience; 3702 Climate Change Science; 3705 Geology; Antarctic; Antarctic Peninsula; Anvers; Palmer Deep; The Antarctic; Antarc*; Antarctica; British Antarctic Survey
• Online Access: https://www.repository.cam.ac.uk/handle/1810/294282; https://doi.org/10.17863/CAM.41381

Basal hydrological systems play an important role in controlling the dynamic behaviour of ice streams. Data showing their morphology and relationship to geological substrates beneath modern ice streams are, however, sparse and difficult to collect. We present new multibeam bathymetry data that make the Anvers-Hugo Trough west of the Antarctic Peninsula the most completely surveyed palaeo-ice stream pathway in Antarctica. The data reveal a diverse range of landforms, including streamlined features where there was fast flow in the palaeo-ice stream, channels eroded by flow of subglacial water, and compelling evidence of palaeo-ice stream shear margin locations. We interpret landforms as indicating that subglacial water availability played an important role in facilitating ice stream flow and controlling shear margin positions. Water was likely supplied to the ice stream bed episodically as a result of outbursts from a subglacial lake located in the Palmer Deep basin on the inner continental shelf. These interpretations have implications for controls on the onset of fast ice flow, the dynamic behaviour of palaeo-ice streams on the Antarctic continental shelf, and potentially also for behaviour of modern ice streams. This research has been supported by the British Antarctic Survey, Natural Environment Research Council, Polar Science for Planet Earth programme.