Erosion and Deposition Mass Movement Goals: 1) Understand what processes wear down the Earth’s surface. 2) Distinguish between the different types of mass movement.

Erosion The process by which natural forces move rocks and soil from one place to another. On Earth water is the primary agent of erosion

Deposition Occurs where agents of erosion lay down sediment (sand, soil, rocks etc.) to make new landforms Erosion and Deposition work together to build up and wear down the land over and over again.

Mass Movement Gravity is the force that moves rock and other material downhill. There are several types of mass movement – moving materials like dirt, rocks and sand down hill.

Landslides Are the most destructive kind of mass movement Occurs when rock and soil move quickly down a steep slope

Landslides

Landslides

Mudflows A rapid movement of a mixture of water, rock and soil. Water may make up 60% of flow. Often occur after heavy rains in dry regions

Mudflows

Mudflows

Slump A mass of rocks and soil slip down hill together in one large piece. Often looks like someone took a bottom piece out from under the slope

Slump

Creep Very slow downhill movement of rock and soil Movement can create weird angles and tilt objects like telephone poles

Creep

Mass Movement The downhill movement of eroded material. Water and gravity are major factors in erosion Question: Why would a landslide be more likely on a steep slope than a gentle slope?