Mudflow

[2] Mudflows contain a significant proportion of clay, which makes them more fluid than debris flows, allowing them to travel farther and across lower slope angles.

[5] Other types of mudflows include lahars (involving fine-grained pyroclastic deposits on the flanks of volcanoes) and jökulhlaups (outbursts from under glaciers or icecaps).

[6] A statutory definition of "flood-related mudslide" appears in the United States' National Flood Insurance Act of 1968, as amended, codified at 42 USC Sections 4001 and following.

Heavy rainfall, snowmelt, or high levels of groundwater flowing through cracked bedrock may trigger a movement of soil or sediments in landslides that continue as mudflows.

The point where a muddy material begins to flow depends on its grain size, the water content, and the slope of the topography.

The term incorporates earth slides, rock falls, flows, and mudslides, amongst other categories of hillslope mass movements.

The upper and lower shelves are located wherever there is a large dip (due to mountain or natural drop) in the mudflow's path.

The world's largest historic subareal (on land) landslide occurred during the 1980 eruption of Mount St. Helens, a volcano in the Cascade Mountain Range in the State of Washington, US[13] The volume of material displaced was 2.8 km3 (0.67 cu mi).

[15][16] By volume, the largest submarine landslide (the Agulhas slide off South Africa) occurred approximately 2.6 million years ago.