The mass wasting phenomenon occurs on both terrestrial and submarine slopes and has been observed on Earth, Mars, Venus, Jupiter’s moons Io and on many other bodies in the Solar System.
The debris transported by mass wasting is not entrained in a moving medium such as water, wind, or ice differing from other processes of erosion. Types of mass wasting include creep, solifluction, rock-falls, debris flows and landslides, each with its own characteristic features, and taking place over timescales from seconds to hundreds of years. It affects geomorphology, most often in subtle, small-scale ways, but occasionally more spectacularly. It also causes problems for civil engineering, particularly highway construction, being able to displace roads, buildings and other construction and can break pipelines. Triggers for mass wasting can be divided into passive and activating (initiating) causes.
Passive causes include:
● Rockandsoillithology. Unconsolidated or weak debris is more susceptible to mass wasting, as are materials that lose cohesion when wet.
● Stratigraphy, such as thinly bedded rock or alternating beds of weak and strong or impermeable or permeable rock lithologies.
● Faults or other geologic structures that weaken therock.
● Topography,such as steep slopes or cliffs.
● Climate, with large temperature swings, frequent freezing and thawing, or abundant rainfall.
● Lack of vegetation.
Activating causes include:
● Undercutting of the slope by excavation or erosion.
● Increased overburden from structures.
● Increased soil moisture.
Methods of mitigation of mass wasting hazards include:
● Construction of fences, walls or ditches to contain rockfall.
● Construction of catchment dams to contain debris flows.
● Improved drainage of source areas.
● Slope stabilisation.