Debris & Earth Flows
Debris & earth flows are mass movements that behave more like liquid than their other mass movement breatheren. This is because debris and earth flows are dependent on high saturation to activate at all. Flows generally only occur as a result of heavy precipitation saturating sediment on hillslopes, activating movement. As water entrains more sediment it becomes denser and more able to pick up further sediment. Eventually, the fluid is dense enough to move massive debris, boulders, vehicles, literally anything in its way. What distinguishes a debris flow from an earth flow is speed and composition. While both are composed of hyper-saturated sediment, debris flows generally contain larger debris, and move dramatically faster than earth flows, which generally contain mostly fine-grained sediment and move more like molasses. Earth flows also tend to occur more on shallower slopes than debris flows.