Landslides

geology · natural disasters · earth science · mountains

Slopes give way. A landslide happens when earth and rock on a slope lose their grip and tumble downward. This can occur on steep mountainsides, gentle hillsides, ocean cliffs, or even on the seafloor.

Water is a trigger. Heavy rain, melting snow, and moisture in the soil can make slopes weaker and more likely to slip. Even water from rivers or ocean waves can loosen the ground.

Many different types. Landslides have lots of names depending on what they're made of: rockfalls drop individual rocks, mudslides are wet and gooey, and debris flows mix everything together like a river of rubble.

They happen everywhere. Landslides occur on mountains, coastal cliffs, underwater slopes, and anywhere else with ground that's angled enough to slide. Some places are riskier than others based on weather and rock types.

Speed varies wildly. Some landslides creep so slowly you'd barely notice them, while others roar downhill in seconds. The fastest ones can travel as fast as a speeding car.