Abstract:

High-precision seafloor topography maps are of great significance in earth science research. Due to the difficulties of measuring high-resolution global coverage of bathymetry directly, a large-scale prediction of seafloor topography relies on gravity data mostly. So, various methods are employed for predicting seafloor topography from gravity data, such as the frequency-domain polarization method, geological-gravity method and iterative analytical method. However, there are some drawbacks in these methods. In this paper, remove-restore method is applied to deal with the issues related to the far-field influences in the iterative analytical method. By combining existing bathymetric models, the simulated experiments are designed to discuss separation methods for the far-field influences and their accuracies are also assessed in inverting seafloor topography. Ultimately, the effectiveness of the remove-restore method is validated in improving seafloor topography by applying to the region of 13.85°N—14.85°N latitude and 117.25°E—118.25°E longitude in the South China Sea. Compared with actual bathymetric data from NGDC, it is concluded that the root mean square error is 90.3 meters and relative error is up to 2.11%. This provides a potential means for improving sparse bathymetric data in ship-measuring areas with high-precision gravity data and the analytical iterative algorithm.

Key words: seafloor topography, gravity anomaly, analytical iterative algorithm, remove-restore method