Abstract
AbstractThe Filchner‐Ronne Ice Shelf, the ocean cavity beneath it, and the Weddell Sea that bounds it, form an important part of the global climate system by modulating ice discharge from the Antarctic Ice Sheet and producing cold dense water masses that feed the global thermohaline circulation. A prerequisite for modeling the ice sheet and oceanographic processes within the cavity is an accurate knowledge of the sub‐ice sheet bedrock elevation, but beneath the ice shelf where airborne radar cannot penetrate, bathymetric data are sparse. This paper presents new seismic point measurements of cavity geometry from a particularly poorly sampled region south of Berkner Island that connects the Filchner and Ronne ice shelves. An updated bathymetric grid formed by combining the new data with existing data sets reveals several new features. In particular, a sill running between Berkner Island and the mainland could alter ocean circulation within the cavity and change our understanding of paleo‐ice stream flow in the region. Also revealed are deep troughs near the grounding lines of Foundation and Support Force ice streams, which provide access for seawater with melting potential. Running an ocean tidal model with the new bathymetry reveals large differences in tidal current velocities, both within the new gridded region and further afield, potentially affecting sub‐ice shelf melt rates.
Highlights
Ice discharge from the Antarctic Ice Sheet (AIS) occurs primarily through ice shelves by iceberg calving and basal melting (Rignot et al, 2013)
We make a comparison with Bedmap2 because this remains the most widely used and up-to-date grid of sub-ice shelf bathymetry beneath the Filchner-Ronne Ice Shelf (FRIS)
We have presented the results of a bathymetric survey of the southeastern FRIS
Summary
S. H. R. Rosier1,2 , C. Hofstede3 , A. M. Brisbourne1 , T. Hattermann4,3 , K. W. Nicholls1 , P. E. D. Davis1 , P. G. D. Anker1, C.-D. Hillenbrand1 , A. M. Smith1 , and H. F. J. Corr1 Citation: Rosier, S. H. R., Hofstede, C., Brisbourne, A. M., Hattermann, T., Nicholls, K. W., Davis, P. E. D., et al (2018). A new bathymetry for the southeastern Filchner-Ronne Ice Shelf: Implications for modern oceanographic processes and glacial history. Journal of Geophysical Research: Oceans, 123, 4610–4623. https://doi.org/10.1029/2018JC013982
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