Mudslide

A mudslide is the most rapid (up to 80 km/h, or 50 mph) and fluid type of downhill mass wasting. It is a rapid movement of a large mass of mud formed from loose soil and water. Similar phenomena include mudflow, mud stream, debris flow (e.g. in high mountains), jökulhlaup, and lahar (from volcanoes, see also pyroclastic flow). These terms cover a broad variety in water content (from loamy mud, to almost liquid, and even steam); material (wet soil, sandy sediments and/or silt, dirt, rock, debris, volcanic ash, small plants, and even trees); length; total mass; and velocity.