A landslide, also known as a landslip, is a geological phenomenon that includes a wide range of ground movements. Rockfalls, deep failure of slopes and shallow debris flows were common. Landslides can occur in offshore, coastal and onshore environments. Although the action of gravity is the primary driving force for a landslide to occur, there are other contributing factors affecting the original slope stability. Typically, pre-conditional factors build up specific sub-surface conditions that make the area/slope prone to failure, whereas the actual landslide often requires a trigger before being released.