What is a landslide? What causes landslide? (2024)

FAQs

What is a landslide? What causes landslide? ›

A landslide occurs because the force of gravity becomes greater than either friction or the internal strength of the rock, soil, or sediment. The amount of friction between a deposit of rock or soil and the slope that it rests on plays a large role in when landslides happen.

A landslide is a mass movement of material, such as rock, earth or debris, down a slope. They can happen suddenly or more slowly over long periods of time. When the force of gravity acting on a slope exceeds the resisting forces of a slope, the slope will fail and a landslide occurs.

There are also various direct methods of preventing landslides; these include modifying slope geometry, using chemical agents to reinforce slope material, installing structures such as piles and retaining walls, grouting rock joints and fissures, diverting debris pathways, and rerouting surface and underwater drainage.

People affected by landslides can also have short- and long-term mental health effects due to loss of family, property, livestock or crops. Landslides can also greatly impact the health system and essential services, such as water, electricity or communication lines.

Landslides have three major causes: geology, morphology, and human activity. Geology refers to characteristics of the material itself. The earth or rock might be weak or fractured, or different layers may have different strength and stiffness. Morphology refers to the structure of the land.

The largest subaerial (on land) landslide in Earth's recorded history was connected with the 1980 eruption of Mount St. Helens volcano in Washington state, USA.

If outdoors: Move quickly away from its likely path, keeping clear of embankments, trees, power lines and poles. Stay away from the landslide area. The slope may experience additional failures for hours to days afterwards.

If you suspect a slide is coming, open downhill windows and doors to allow debris that could pass through the house to exit. To escape a landslide, go up! Upstairs, and up on top of furniture, to have the best chance to stay on top of the debris. In the very unlikely event you're trapped, never give up.

Fences, retaining walls, utility poles, or trees tilt or move. A faint rumbling sound that increases in volume is noticeable as the landslide nears. Unusual sounds, such as trees cracking or boulders knocking together, might indicate moving debris.

It is one of the natural hazards and can be a disaster if the damages occur in large amounts. According to the Oxford learners dictionary, "landslides is a mass of earth, rock, etc. that falls down the slope of a mountain or a cliff ".

What type of land is prone to landslides? ›

Landslides typically occur on slopes with fractured materials (e.g., rock, debris, ice), deep soils, or thin soils over bedrock.

Countries with the most amount of land at high risk of landslides include Italy, Austria, China, the Philippines and Ethiopia.

An average of 25-50 people are killed by landslides each year in the United States. The worldwide death toll per year due to landslides is in the thousands. Most landslide fatalities are from rock falls, debris flows, or volcanic debris flows (called lahars).

If you do get stuck in the path of a landslide move uphill as quickly as possible. Avoid river valleys and low-lying areas during times of danger. If you are near a stream or channel, be alert for any sudden increase or decrease in water flow or water that changes from clear to muddy.

Landslides typically occur on slopes with fractured materials (e.g., rock, debris, ice), deep soils, or thin soils over bedrock.