landslide, rapid slipping of a mass of earth or rock rock, aggregation of solid matter composed of one or more of the minerals forming the earth's crust. The scientific study of rocks is called petrology. Rocks are commonly divided, according to their origin, into three major classes—igneous, sedimentary, and
..... Click the link for more information. from a higher elevation to a lower level under the influence of gravity and water lubrication. More specifically, rockslides are the rapid downhill movement of large masses of rock with little or no hydraulic flow, similar to an avalanche avalanche, rapidly descending large mass of snow, ice, soil, rock, or mixtures of these materials, sliding or falling in response to the force of gravity. Avalanches, which are natural forms of erosion and often seasonal, are usually classified by their content such
..... Click the link for more information. . Water-saturated soil or clay on a slope may slide downhill over a period of several hours. Earthflows of this type are usually not serious threats to life because of their slow movement, yet they can cause blockage of roads and do extensive damage to property. Mudflows are more spectacular streams of mud that pour down canyons in mountainous regions during major rainstorms where there is little vegetation to protect hillsides from erosion. The runoff from the storm and mud becomes a thin slurry that funnels down the canyons until it thickens and stops. Earthquakes earthquake, trembling or shaking movement of the earth's surface. Most earthquakes are minor tremors. Larger earthquakes usually begin with slight tremors but rapidly take the form of one or more violent shocks, and end in vibrations of gradually diminishing force
..... Click the link for more information. also may cause landslides by shaking unconsolidated or weathered material from slopes. Rockslides triggered by an earthquake in Montana in 1959 caused an entire mountainside to slide into the Madison River gorge, killing 27 people in its path, damming the gorge, and forming a new lake. Humans have triggered a number of tragic landslides that have caused great damage and loss of life. In the Los Angeles area of California, extensive real estate development carried out on hillsides has resulted in widespread mudflows after winter rains have saturated the over-steepened embankments of soil. In some areas, slow-moving earthflows have been initiated by the lubrication of certain types of underlying clays by septic tank effluent. Submarine slides, or a sliding mix of seawater and mud, are called turbidity currents. Undersea landslides can travel several hundred miles across very gradual slopes, riding on a thin film of water that reduces friction.

landslide

The movement of a mass of rock or soil down a slope. The term is used to describe a variety of phenomena, from rock falls to the gradual downhill flow of soil. Landslides occur when the force of gravity acting on the materials within a slope overcomes the material's resistance to shearing. Among the processes that can lead to a landslide are the steepening of a slope by natural erosion or excavation, the overloading of the slope by an inflow of water, and the motion caused by an earthquake.

landslide (redirected from Landslides)

landslide

landslide
(redirected from Landslides)