Landslides are a form of mass wasting that includes the movement of a large area of land under the force of gravity. This can occur as a soil movement, rockfalls, mudflows, debris flows, etc. A landslide can take place in a variety of environments such as mountains , coastal cliffs, underwater submarine slides , etc.
This type of land movement occurs where there is a steep slope or a gentle slope that cannot hold the land tight to itself. Gravity is the primary force of driving the land from one place to another. Generally, a landslide is triggered by a particular event such as heavy rainfall, earthquakes, building roads by cutting mountains, etc. There are different types of landslides.
The two most common forms of landslide include debris landslide and earthflow. Debris landslide is caused by the saturation of the debris matter with water that develops into a mudflow or a debris flow. Figure 8. Trees with curved trunks are often signs that the hillside is slowly creeping downhill. Creep is the imperceptibly slow, steady, downward movement of slope-forming soil or rock. Movement is caused by shear stress sufficient to produce permanent deformation, but too small to produce shear failure.
There are generally three types of creep:. Curves in tree trunks indicate creep because the base of the tree is moving downslope while the top is trying to grow straight up figure 8. Tilted telephone or power company poles are also signs of creep. Answer the question s below to see how well you understand the topics covered in the previous section.
This short quiz does not count toward your grade in the class, and you can retake it an unlimited number of times. Use this quiz to check your understanding and decide whether to 1 study the previous section further or 2 move on to the next section.
Privacy Policy. Skip to main content. Module Mass Movement. Search for:. Types of Mass Movement Identify and describe types of mass movement. Figure 6. The term "landslide" encompasses a broad assortment of ground movements like debris flow, mudflow, deep-seated slope failures, and rockfalls. Landslides can also take place underwater submarine landslide , and in coastal environments. Although gravity is the vital driving force of landslides, there are many other factors like deforestation which affect the stability of the slopes.
An avalanche is a geological phenomenon which occurs during winter. It is the movement of a large mass of ice or snow down a sloppy terrain. The movement of debris or rocks down a slope in a similar manner is also known as avalanches.
An avalanche is triggered by the unique interaction between the terrain, weather, and the snow. Numerous human activities like skiing can also trigger an avalanche.
The effects include uprooted trees and degraded soil, buried buildings and settlements, damage to crops and infrastructure such as roads, and injury and death to humans and animals.
We consider landslides to be natural but human activities like deforestation or mining can also induce landslides. This film is part of a Disaster Awareness series produced in by t he National Institute of Higher Education, Research, Science and Technology Trinidad and Tobago in collaboration with UNESCO, which aims to educate general audiences on the natural and man-made factors that contribute to hazardous phenomena, historical disasters that they have caused both within the Caribbean and worldwide, their impact on our lives and ways in which their disastrous consequences can be mitigated.
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