Three types of mass movements include falls, slides and flows. A mass movement is the movement of a section of a cliff or hill down a slope due to gravity. It can be triggered by heavy rains, rivers or earthquakes.
The name of a mass movement is determined by how much water is present and how quickly the mass moves. Falls are movements that involve rocks falling from the air and landing at the bottom. Slides involve rock or soil moving suddenly and quickly down a slope. Flows are mixtures of water, rock and sediment. They can be large, blocking roads and burying entire cities.