Modern sedimentation, circulation and life beneath the Amery Ice Shelf, East Antarctica

The surface sedimentary record from six cores collected from beneath the Amery Ice Shelf, East Antarctica, provides a unique view of the sedimentary and oceanographic processes in this sub-ice shelf setting. The composition and age of the surface sediments indicate spatial variations in ice shelf ca...

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Bibliographic Details
Published in:Continental Shelf Research
Main Authors: Post, AL, Galton-Fenzi, BK, Riddle, MJ, Herraiz-Borreguero, L, O'Brien, PE, Hemer, MA, McMinn, A, Rasch, D, Craven, M
Format: Article in Journal/Newspaper
Language:English
Published: Pergamon-Elsevier Science Ltd 2014
Subjects:
Earth Sciences
Geology
Marine Geoscience
Amery
Amery Ice Shelf
East Antarctica
Antarc*
Antarctica
Ice Shelf
Online Access:https://doi.org/10.1016/j.csr.2013.10.010
http://ecite.utas.edu.au/88928
Description
Summary:The surface sedimentary record from six cores collected from beneath the Amery Ice Shelf, East Antarctica, provides a unique view of the sedimentary and oceanographic processes in this sub-ice shelf setting. The composition and age of the surface sediments indicate spatial variations in ice shelf cavityocean interaction, which are consistent with patterns of ocean inflow and outflow modelled and observed beneath the ice shelf. Sediments within 100km of the ice shelf front (site AM01) show the greatest open ocean influence with a young surface age and the highest total diatom abundance, compared to older ages and lower diatom abundances at sites deeper in the cavity (AM03AM06). The variable marine influence between sites determines the nature of benthic communities. Seabed imagery indicates the existence of sessile suspension feeders in areas of strong marine inflow (site AM01b), while grazers, deposit feeders and a few suspension feeders occur at sites more distal from the shelf calving front where the food supply is lower (sites AM03 and AM04). Understanding the sedimentary and oceanographic processes within the sub-ice shelf environment allows better constraint of interpretations of down core sediment records, an improved understanding of the nature of biological communities in sub-ice shelf environments, and a baseline for determining the sensitivity of the system to any future changes in ocean dynamics.

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