Improving Accuracy of Altimeter-derived Marine Gravity Anomalies for Geological Structure Research in the Vietnam South-Central Continental Shelf and Adjacent Areas

Abstract

In recent years, the satellite altimeter technology allows to enhance the marine investigation in any area. Up to now, many scientific studies have attempted to improve the accuracy and resolution of altimeter-derived gravity anomalies and have produced a gravity grid with interval of 1' × 1' for most the oceans all over the world. However, this gravity anomalies are not very high accuracy and have a large difference compared to shipboard gravity anomalies, especially in the coastal and islands areas. The purpose of this article is to improve the accuracy of altimeter-derived marine gravity anomalies for geological structure research in the Vietnam South-Central continental shelf and adjacent areas. The least squares collocation method is used to correct the altimeter-derived marine gravity data based on the shipboard gravity data in order to improve the accuracy of marine gravity anomalies. In this article, the altimeter-derived marine gravity anomalies are taken from Sandwell, D. T., et al., (V24.1) and the shipboard gravity anomalies are from the surveyed projects between Vietnam, Russia and other countries. Here, comparison of both those data has brought a mean-squared error is about ±9.358 mGal. After correcting, the mean-squared error between the corrected-altimeter-derived marine gravity and shipboard gravity anomalies are improved from ±9.358 to ±1.208 mGal (for the altimeter data coincided with shipboard track). Also, in this article, the Cenozoic sedimentary density and thickness are determined through the 3D interpretative methods of the above-corrected gravity anomalies in combination with seismic data. The achieved results realize how the efficiency and actuality of the corrected-altimeter-derived marine gravity anomalies for the detailed researches of geological structures. Especially, it is more meaningful in the remote or sparsely surveyed regions.