• Low-angle submarine landslides are more hazardous than steep ones, with sliding angles often below 5° and large volumes.
• The failure mechanism involves combined effects of rapid sedimentation, high-pressure gas activity, and seismic events.
• High-pressure gas acts as a long-term preconditioning factor by elevating pore pressures and reducing shear resistance.
• Frequent or moderate earthquakes ultimately trigger local failure in predisposed slopes.