What are Landslides

A landslide is a sudden movement of rock, soil, and debris (broken pieces of rock and dirt) down a slope (a hillside or mountain). Landslides are important to understand because they can happen quickly and cause serious damage to communities and the environment.

Landslides often happen during or after heavy rain. When water soaks into the ground, it makes the soil heavy and slippery, like wet mud on a playground slide. The weight of the water-soaked soil can cause it to slide downhill. Earthquakes can also trigger (start or cause) landslides by shaking the ground and loosening rocks and soil. Volcanic eruptions and human activities like cutting into hillsides for roads and buildings can trigger landslides too.

When a landslide occurs, it can bury homes, block roads, dam rivers, and completely change the shape of the land in just minutes. Hillsides that have been cleared of trees are especially vulnerable (at risk or in danger) because plant roots help hold the soil in place. Without these roots acting like anchors, the soil is more likely to slide away.

Understanding what causes landslides helps people make safer choices about where to build homes and how to protect hillsides from sliding.

Interesting Fact: The fastest landslide ever recorded moved at speeds over 200 miles per hour, faster than most cars on a highway!