Flows occur when unconsolidated fine grained sediment, e.g. silts and clays, mix with large volumes of water. They're common in weak rocks such as clay or unconsolidated sands. They become saturated, lose their cohesion, and flow downslope. Heavy rainfall, combined with high waves and tides can contribute to saturation. Earthflows are more viscous than mudflows, and contain larger sediment. In cold environments, earthflows known as solifluction occur in the unfrozen layer between the permafrost and the tundra vegetation turf.
