TOPOGRAPHIC FEATURES OF THE SEAMOUNTS IN THECENTRAL BASIN OF THE SOUTH CHINA SEA:BASED ON MULTI-BEAM BATHYMETRIC DATA

Upon the multi-beam bathymetric survey of the central basin of the SCS (South China Sea) in the past decades, submarine topography of the basin has become clearer. This paper is devoted to the study of the topographic features of seamounts and knolls in SCS central basin based on the multi-beam bathymetric data from Guangzhou Marine Geological Survey. Three dimensional topographic maps of typical seamounts and knolls are exhibited to reveal how the seamounts and knolls in SCS central basin look like. Statistics suggest that there are about 46 seamounts, 90 knolls with height difference in 1000-500m and about 100 knolls with height difference in 500-200m in the SCS central basin. Multi-beam bathymetric data shows finer terrain information than ever before. For examples, volcanic vents on the top of seamounts and knolls are discovered and steep slopes observed on some seamounts and knolls, probably caused by faults. Based on the distribution pattern of steep slopes, we inferred that the Zhongnan fault is actually a fault zone, consisting of two parallel N-S faults and the region between them.