Amundsen Sea Bathymetry: The Benefits of Using Gravity Data for Bathymetric Prediction

• Main Authors: McMillan, M, Shepherd, A, Vaughan, DG, Laxon, S, McAdoo, D
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC 2009
• Subjects: Altimetry; Arctic regions; gravity measurement; satellites; sea floor; terrain mapping; ANTARCTIC ICE-SHEET; ERS-1 SATELLITE ALTIMETRY; MARINE GRAVITY; EXPERIMENTAL ISOSTASY; FIELD; OCEAN; Amundsen Sea; Antarctic; Arctic; West Antarctica; Antarc*; Antarctica; Ice Sheet
• Online Access: http://discovery.ucl.ac.uk/154927/

Bathymetric charts are essential for modeling oceanic processes, yet, in remote areas, direct measurements of seafloor depth are often scarce. It is possible to augment sparse depth soundings with dense satellite-derived gravity data to provide additional bathymetric detail in regions devoid of sounding data. We demonstrate this method by using marine gravity derived from the European Remote Sensing (ERS-1) satellite altimeter, combined with depth soundings, to form a bathymetric prediction of the Amundsen Sea, West Antarctica. We estimate the root mean square error of depth estimates at unsurveyed locations in our solution to be similar to 120 m. We use a Monte Carlo method to assess the value of gravity as a bathymetric predictor in sparsely surveyed regions by comparing our solution to predictions formed from depth soundings alone. When less than similar to 11% of 10-km grid cells contain depth soundings, inclusion of gravity data improves the depth accuracy of the solution by up to 17%, as compared to a minimum curvature surface interpolation of the depth soundings alone. When depth data are sparse, our gravity-derived prediction reveals additional short-wavelength bathymetric features, such as troughs on the continental shelf, which are not resolved by interpolations of the depth soundings alone.