• Low-angle submarine landslides in the Pearl River Mouth Basin are primarily triggered by a combination of rapid sedimentation, high-pressure gas accumulation, and seismic events.
• High-pressure gas acts as a long-term preconditioning factor by elevating pore pressures and reducing shear strength, predisposing the slope to failure.
• Sea-level fluctuations control sedimentation patterns, leading to the formation of low-permeability strata that trap gas and promote overpressure.
• Frequent or moderate earthquakes serve as the final trigger for local failure in an already destabilized slope.