Abstract: In this study, the submarine topography of the Amundsen Sea in Antarctica was inverted at 1'×1' resolution using the Gravity Geologic Method (GGM), shipboard single-beam echosounding data and altimeter-derived gravity anomaly data, version V30.1, from the Scripps Institution of Oceanography model, as input. First, an accuracy analysis confirmed that the GGM-based model yielded the highest overall accuracy, compared with other universal bathymetric models. Then, the influence of the number of control points and of the topographic relief on inversion accuracy was analyzed. Results showed that topographic relief strongly influenced inversion accuracy and that increasing the number of control points improved the inversion accuracy. Finally, the research area was partitioned by depth to analyze the relationship between density contrast and external factors. Density contrast was markedly influenced by topographic relief, thus the GGM was used in this study to calculate local interval partitioning depending on the optimal density contrast depth. Compared with global optimal density contrast inversion of seafloor topography, the method used in this study showed considerably higher accuracy.

Key words: Gravity Geologic Method, gravity anomaly, seabed topography, Amundsen Sea, bathymetric division