Mapping Submarine Landslide: A Case Study in Northern Continental Slope of the South China Sea

Geographical Information Systems is a useful tool for marine geohazard mapping. This paper describes an integrated and systematic map-based approach for identification and characterization of submarine landslide with multidisciplinary data such as multibeam bathymetric data, multichannel seismic data, sidescan sonar and so on. Taking Liwan 31 gas field in northern continental slope of Southern China Sea as a case study, a regional database is established to provide convenient services to manage search and extract the target data for geohazard mapping and identification. Bathymetric map and seismo-geomorphologic map are calculated and produced with GIS to establish an elementary understanding of geomorphologic features. With this integrated approach, dozens of landslides are identified in the study area and they are featured as small and multiple superimposed failure scars. Fundamental information of landslides can also be provided for further detail interpretation, quantification and assessment of their mechanism and potential risks.