EAS Mass Movements

What causes large quantities of rock to slide or fall down slope?

• Gravity only

• Gravity & destabilization

• Destabilization only

• Rain, water, and wind

Rock breaks off of the cliff, and falls to the valley below.

• Rockfall

• Rock slide

• Landslide

• Debris flow

Large masses of rock break free from the slope of a mountain, and slide down the slope. The rock crumbles and disintegrates as it slides.

• Rockfall

• Rock slide

• Landslide

• Debris flow

Large masses of dry soil, rock and sediments slide down the slopes of mountains. They start to slide because of oversteepening or by vibrations.

• Rockfall

• Rock slide

• Landslide

• Debris flow

Large masses of very wet soil, rock and sediments slide down the slopes of mountains. They start to slide because of too much rain and steep slopes.

• Rockfall

• Rock slide

• Landslide

• Debris flow

Large masses of ice, snow, and rock that break free from mountain slopes and sweep very fast through the valleys. They are caused by too much snow and too much weight pulling them down.

• Avalanche

• Lahar

• Talus

• Mudslide

Crumbled rock rubble and debris in the valleys below cliffs. This rock rubble is created by rockfall smashing into the valley below.

• Avalanche

• Lahar

• Talus

• Mudslide

A very fast moving mudslide made of volcanic ash mixed with water. These form when a volcano erupts, the glaciers near the summit of the mountain melt, and wash the ash like river into the valleys below.

• Avalanche

• Lahar

• Talus

• Mudslide

A very fast moving river of soil and mud caused by too much rain. This washes the soil and mud into the valleys.

• Avalanche

• Lahar

• Talus

• Mudslide

What mass movement is shown in the picture?

• Rockfall

• Rockslide

• Landslide

• Debris flow