Preprints
https://doi.org/10.5194/essd-2021-245
https://doi.org/10.5194/essd-2021-245

  26 Jul 2021

26 Jul 2021

Review status: this preprint is currently under review for the journal ESSD.

Water masses distribution offshore the Sabrina Coast (East Antarctica)

Manuel Bensi1, Vedrana Kovačević1, Federica Donda1, Philip E. O'Brien2, Linda Armbrecht3, and Leanne Armand4 Manuel Bensi et al.
  • 1National Institute of Oceanography and Applied Geophysics (OGS), Trieste, 34010, Italy
  • 2Department of Environmental Sciences, Macquarie University, Sydney, Australia
  • 3Australian Centre for Ancient DNA, Department of Ecology & Evolutionary Biology, School of Biological Sciences, The University of Adelaide, South Australia 5005, Australia
  • 4Australian National University, Canberra, Australia

Abstract. Current glacier melt rates in West Antarctica substantially exceed those around the East Antarctic margin. The exception is Wilkes Land where, e.g., Totten Glacier, underwent significant retreat between 2000 and 2012, underlining its sensitivity to climate change. This process is strongly influenced by ocean dynamics, which in turn changes in accordance with the evolution of the ice caps. Here, we present oceanographic data (temperature, salinity, density, dissolved oxygen) collected for the first time offshore the Sabrina Coast (East Antarctica), from the continental shelf break to ca 3000 m depth during austral summer 2017.

The main water masses are identified by analysing thermohaline properties: the Antarctic Surface Water with θ > −1. 5 °C and S < 34.2 (σθ < 27.55 kg m−3), the Winter Water with −1.92 < θ < −1.75 °C and 34.0 < S < 34.5 (27.55 < σθ < 27.7 kg m−3), the modified Circumpolar Deep Water with θ > 0 °C and S > 34.5 (σθ > 27.7 kg m−3), and Antarctic Bottom Water with −0.50 < θ < 0 °C and 34.63 < S < 34.67 (27.83 < σθ < 27.85). The latter in this region is a mixture of dense waters originating from the Ross Sea and Adélie Land continental shelves, and is affected by the mixing process they undergo as they move westward along the Antarctic margin and interact with the locally formed dense waters, and with the warmer and saltier Circumpolar Deep Water.

The spatial distribution of water masses offshore the Sabrina Coast also appears to be strongly linked with the complex morpho-bathymetry of the slope and rise area, supporting the hypothesis that downslope processes contribute to shaping the architecture of the distal portion of the continental margin.

Manuel Bensi et al.

Status: open (until 11 Oct 2021)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on essd-2021-245', Anonymous Referee #1, 23 Aug 2021 reply

Manuel Bensi et al.

Manuel Bensi et al.

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Short summary
The Totten Glacier (Sabrina Coast, East Antarctica) has undergone significant retreat in recent years, underlining its sensitivity to climate change and its potential contribution to global sea-level rise. The melting process is strongly influenced by ocean dynamics and the spatial distribution of water masses appears to be linked to the complex morpho-bathymetry of the area, supporting the hypothesis that downwelling processes contribute to shaping the architecture of the continental margin.