What are the geological causes of landslides?

What are the geological causes of landslides?

landslide, also called landslip, the movement downslope of a mass of rock, debris, earth, or soil (soil being a mixture of earth and debris). Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.

What are the processes of landslides?

The term “landslide” describes a wide variety of processes that result in the downward and outward movement of slope-forming materials including rock, soil, artificial fill, or a combination of these. The materials may move by falling, toppling, sliding, spreading, or flowing.

What geological features make landslides more common?

Landslides are associated with hilly or mountainous landscapes. They are also common along coastlines and river valleys. Landslides occur most frequently in regions where climate and precipitation, bedrock and soil conditions, and slopes are susceptible to failure.

How does geology affect the landslide?

Several factors can increase a slope’s susceptibility to a landslide event. Rock type: the type of rocks in the slope, and their combination, can increase the chance of a landslide. Grain shape: the shape of the grains that make up a rock can affect the risk of a landslide. Jointing and orientation of bedding planes.

What is the main trigger of a landslide?

Bottom line: Landslides are mainly caused by gravity acting on weakened rocks and soil that make up a sloping area of land. Both natural and human-related activities can increase the risk for landslides. Water from heavy rainfall is a frequent trigger for landslides.

What is landslide in geography?

A landslide is defined as the movement of a mass of rock, debris, or earth down a slope. Landslides are a type of “mass wasting,” which denotes any down-slope movement of soil and rock under the direct influence of gravity.

What are the human induced factors that trigger landslides?

Human activities can increase landslide risks. They include clear-cutting, mining and quarrying, bad agricultural practices, and construction activities.

How do tectonic plates cause landslides?

Any time plate tectonics move the soil that covers them moves with it. When earthquakes occur on areas with steep slopes, many times the soil slips causing landslides. Heavy Rainfall: When sloped areas become completely saturated by heavy rainfall many times landslides can occur.

How do rivers affect landslides?

More than 90% of the landslides occur in meander bends and are related to river erosion. Failures in the bedrock appear to be translational whereas those higher on the valley wall in Pleistocene sediments are largely rotational.

How do earthquakes cause landslides?

When earthquakes occur on areas with steep slopes, many times the soil slips causing landslides. Furthermore, ashen debris flows caused by earthquakes can also trigger mass movement of soil. Heavy Rainfall: When sloped areas become completely saturated by heavy rainfall many times landslides can occur.

Which of the following can trigger a landslide quizlet?

Which of the following can trigger a mudslide or landslide? Both earthquake shocks and vibrations from machinery and traffic can trigger a landslide. The accumulation of rock by a rock fall is called a talus.

Which natural phenomenon can trigger a landslide?

Landslides are induced by climatic conditions such as heavy rainfalls, snowfalls or natural phenomena such as volcanic activity or earthquakes. Human activities such as deforestation, mining, constructions, vibrations from big machines, etc. may also cause a landslide.

What are landslides and what causes them?

Landslides occur when gravity overcomes the force of friction. Several common causes of landslides are: Water: Perhaps the most common trigger of a landslide, water reduces the friction between the bedrock and the overlying sediment, and gravity sends the debris sliding downhill.

What is a landslide and what causes one?

The primary cause of a landslide is the influence of gravity acting on weakened materials that make up a sloping area of land. While some landslides occur slowly over time (e.g., land movement on the order of a few meters/yards per month), the most destructive ones happen suddenly after a triggering event such as heavy rainfall or an earthquake.

What are the natural causes of landslides?

Natural causes of landslides include earthquakes, volcanic eruptions, the undercutting of cliffs and banks by water erosion due to tidal waves, and the elevation of pore water pressure by prolonged rainfall and seepage. All of these natural causes are influencing factors of landslides.