A review of geohazards on the northern continental margin of the South China Sea

Abstract Crustal instability to induce the geohazards often results from both the internal tectonic dynamics and external sediment processes. Thus, the detailed geodynamics and kinematics of geohazards are important for understanding the tectonic evolutionary process and evaluating potential geohazards. This paper focuses on the active faults, submarine landslides, earthquakes as well as submarine canyons geomorphology description and kinetics explanation in the northern South China Sea (SCS) continental margin. Firstly, we have estimated the spatial extent, fault-plane geometry and faulting behaviors of the submarine active faults, such as the Littoral Fault Zone, based on cumulative deformation recorded by geophysical seismic reflections and geomorphic markers. We also analyzed the reactivation of preexisting structures, as well as the spatial and temporal distribution and migration of the submarine landslides and canyons. Then, several conceptual models and a comprehensive study of some of the different factors that contributed to the geohazard chain are conducted based on pre-existing theory and available literature. This review study indicates: (i) geohazards of different phases and geohazard chain are generally triggered by both early-phase tectonics-dominated and later-phase sedimentation-dominated processes; (ii) the fault geometric and stress segmentation may have played an important role in controlling on the uneven and asymmetric distribution of earthquakes and submarine canyons of the northern SCS, Especially, the ENE-striking preexisting Littoral Fault Zone is the major seismogenic structure along the Southchina coastline; (iii) the tectono-sedimentary coupling induced landslide and slope failure that has help to shape the modern coastal and slope geomorphology.