Fangliao Slide - a large slope failure in the upper Kaoping Slope off southwest Taiwan

Based on seismic reflection profiles and multi-beam bathymetric data, a large submarine landslide named Fangliao Slide is mapped for the first time off SW Taiwan. The Fangliao Slide occurred on the continental slope to the west of the Fangliao Canyon at water depths between 420 and 900 m. The seafloor of the Fangliao Slide has a gentle slope angle (similar to 1-2 degrees). The landslide covers an area of similar to 15 km length and similar to 10 km width and a volume of similar to 26 km(3). The headwall of the landslide has similar to 30 m vertical offset at the southern flank of mud diapir MD7-1, and the sidewalls are bounded by fault A in the west and faults C and D in the east. The sliding area is composed of five bathymetric terraces, indicating that the slope failures have occurred several times. The Fangliao Slide can be divided into an upper domain and a lower domain, separated at the water depth of similar to 600 m where the gas hydrate off SW Taiwan becomes dissociate. The initial slope failure of the Fangliao Slide was probably linked to mud diapirism of MD7-1 and the slope failure in the lower domain was probably augmented by the gas hydrate dissociation. The seafloor morphology in the lower domain is therefore more corrugated than in the upper domain.