A debris flow or debris flow , in geological professional use with the English word debris flow called, is a mass movement , in which pebbles , stones and rocks, in some cases, plants, trees or other debris in a muddy transported matrix as a continuous stream downhill. Debris flows can reach speeds of up to 20 meters per second.
The density of the material contained in a debris flow is 2–2.5 grams per cubic centimeter. The water content of the debris flow, which causes the thixotropic behavior of the flow, is at least 5%, but can be significantly higher. The friction at the base of the stream is greatly reduced by the water content and the turbulent flow. The pebbles are held in suspension by the viscosity of the matrix and its high density. A stream of debris can transport large blocks and flow on almost flat surfaces.
- Heinrich Bahlburg, Christoph Breitkreuz: Fundamentals of geology. 5th edition, Springer Spectrum 2017, ISBN 978-3-662-54930-8 , p. 79 f.