swmaio.blogg.se

Displacement of material by landslides causes the absence of material uphill and the deposition of new material downhill, and careful observation can identify the evidence of that displacement.

Note that there are many exceptions, and a landslide does not have to have these features. Landslides have several identifying features that can be common across the different types of mass wasting. A special type of soil creep is solifluction, which is the slow movement of soil lobes on low-angle slopes due to soil repeatedly freezing and thawing in high-latitude, typically sub-Arctic, Arctic, and Antarctic locations. Creep is indicated by curved tree trunks, bent fences or retaining walls, tilted poles or fences, and small soil ripples or ridges. They are still poorly understood but are known to travel for long distances, even in places without significant atmospheres like the Moon.Ĭreep is the imperceptibly slow downward movement of material caused by shear stress sufficient to produce permanent deformation in unconsolidated material. Some of the largest and fastest flows on land are called sturzstroms, or long-runout landslides. Flows are commonly separated into debris flow (coarse material) and earthflow (fine material) depending on the type of material involved and the amount of water. Įxamples of some of the types of landslides.įlows are rapidly moving mass-wasting events in which the loose material is typically mixed with abundant water, creating long runouts at the slope base. Mass wasting movement type and primary earth material. Primary Material Type and Common Name of Slide Slides can be further subdivided into rock slides, debris slides, or earth slides depending on the type of the material involved (see table).

Translational slides often are rapid movements along a plane of distinct weakness between the overlying slide material and the more stable underlying material. Rotational slides commonly show slow movement along a curved rupture surface. Falls are strongly influenced by gravity, mechanical weathering, and water. Movement occurs as free-falling, bouncing, and rolling. Rocks separate along existing natural breaks such as fractures or bedding planes. Falls are abrupt rock movements that detach from steep slopes or cliffs. The most common mass-wasting types are falls, rotational and translational slides, flows, and creep.