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USGS CMG InfoBank: Mudflows and Debris Flows

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Comment: 15:50 - 16:48 (00:58)
Source: Annenberg/CPB Resources - Earth Revealed - 16. Mass Wasting
Keywords: "mass wasting", "mudflow", "debris flow", creep, slump, landslide, water, movement, viscosity, density, sand, silt, boulder, rainfall, snow, gravity, "geologic hazard"

Our transcription: Mud and debris flows which move faster than creep, slump, and some landslides are the product of loose unstable material mixed with water.
Their consistency ranges from stiff mud to a soup-like fluid.
Because of their viscosity and high density, mud and debris flows are a form of mass wasting that can tear homes from their foundations and carry lighter objects like automobiles for substantial distances.
The debris that comprises these flows can range in size from grains of silt and sand to boulders.
Once the debris has accumulated, all that's needed is an intense rainstorm or snow melt to saturate the area with water.
At that point, gravity can move the debris, and as flows overwhelm low lying areas, the mass wasting process is set in motion.

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Page Last Modified: Thu Oct 31 04:27:01 PDT 2013  (chd)