The cavity under the Amery Ice Shelf, East Antarctica

• Main Authors: Galton-Fenzi, BK, Maraldi, C, Coleman, R, Hunter, J
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2008
• Subjects: Amery Ice Shelf; East Antarctica; physical oceanography; sub-ice-shelf cavity; ocean circulation; Amery; Antarc*; Antarctica; Antarctica Journal; Ice Shelf; Ice Shelves; Journal of Glaciology
• Online Access: https://eprints.utas.edu.au/8443/; https://eprints.utas.edu.au/8443/1/Galton-Fenzi_etal_JGlac_2008.pdf; http://www.igsoc.org/journal/54/188/t08J021.pdf

Ocean circulation under ice shelves and associated rates of melting and freezing are strongly influenced by the shape of the sub-ice-shelf cavity. We have refined an existing method and used additional in situ measurements to estimate the cavity shape under the Amery Ice Shelf, East Antarctica. A finite-element hydrodynamic ocean-tide model was used to simulate the major tidal constituents for a range of different sub-Amery Ice Shelf cavity water-column thicknesses. The data are adjusted in the largely unsurveyed southern region of the ice-shelf cavity by comparing the complex error between simulated tides and in situ tides, derived from GPS observations. We show a significant improvement in the simulated tides, with a combined complex error of 1.8 cm, in comparison with past studies which show a complex error of ∼5.3 cm. Our bathymetry incorporates ice-draft data at the grounding line and seismic surveys, which have provided a considerable amount of new data. This technique has particular application when the water column beneath ice shelves is inaccessible and in situ GPS data are available.