Mass Movement

Vocabulary Erosion Sediment Deposition Infiltration Percolation Saturation Mass Movement

Erosion: process by which natural forces such as wind, water, ice, and gravity, move weathered rock and soil from one place to another.

Sediment: the material moved by erosion

Deposition: process in which sediment is laid down in new locations

Infiltration The process by which water on the ground surface enters and is absorbed by the soil

Percolation The flow of water through soil and porous or fractured rock.

Saturation Saturation of soil is a condition in which all easily drained voids between soil particles are temporarily or permanently filled with water

What is Mass Movement? Mass movement is any of the processes that move sediment downhill. Mass movement can be rapid or slow.

Four Types of Mass Movement Landslides Mudflows Slump Creep

Landslides Occurs when rock and soil slide rapidly down a steep slope. Some contain huge masses of rock and soil, but some contain small amounts. Some landslides occur where road builders have cut into hills or mountains

Mudflows Rapid downhill movement of a mixture of water, rock, and soil. Amount of water in a mudflow can be as high as 60%. Often occur after heavy rains in a normally dry area. An earthquake can trigger both mudflows and landslides.

Slump A type of mass movement in which rock and soil rapidly slips down a slope in one large mass. A slump often occurs when water soaks the bottom of soil that is rich in clay.

Creep The very slow downhill movement of rock and soil. It can occur on gentle slopes. Often results from the freezing and thawing of water in cracked layers of rock beneath the soil. Creep may tilt objects such as gravestones, telephone poles, and fence posts at spooky angles.

Watch this video and discuss. “The World’s Largest Landslide Laboratory” – Discovery Education https://app.discoveryeducation.com/learn/videos/734f4031-2368-480c-abe6- bb8089759459?hasLocalHost=false