Only use ship-track gravity data with caution: a case-study around Australia

Abstract

Much of the ship-track marine gravity data in the Australian national gravity database must not be relied upon because several large (>900 mGal) biases exist in them. These biases were detected and cross-validated through comparisons with marine gravity anomalies derived from re-tracked multi-mission satellite altimetry and a recent satellite-only global geopotential model derived from the Gravity Recovery And Climate Experiment (GRACE). This shows the need to carefully screen ship-track gravity data to ensure that they have been crossover-adjusted before they are relied upon in any Earth-science study.

Key Words:

• altimetry
• Australia
• geodesy
• global geopotential models
• gravity
• marine gravimetry

Acknowledgements

Thanks go the many providers of data, who are named and/or cited in this paper. This research was supported under the Australian Research Council's Discovery Projects funding scheme (project number DP0663020). Thanks also to the two anonymous journal reviewers. This is The Institute for Geoscience Research publication number 128.