Chapter 4 Lesson 3

Weathering and Erosion

Weathering The process through which rocks or other materials are broken down..

Types of Weathering Physical – caused by pushing, pulling, rubbing or temperature changes. Chemical – caused by chemicals breaking down rocks Often caused by acid rain Or by certain chemicals in ground water

Frost Wedging

Erosion The process by which rock is moved from one place to another.

Running water and waves Ways Rocks Can Erode Running water and waves Wind Ice (Glacial) Gravity

Water Water weathers rock by dissolving it

Water Erosion Rivers, streams, and runoffs

Mudslides & Landslides Mudslide – movement of a large amount of wet soil and rocks down a slope Happens after lots of rain Landslide – movement of a large amount of dry rock and soil down a slope May occur after volcanic eruptions and earthquakes

Landslides

Mudslides

Glaciers - a large mass of slowly flowing ice

Cirque – steep hollow shape bowl in a mountain formed by a glacier.

Deposition – process by which eroded materials are dropped off in another place

Meanders – gentle loops in rivers Sediment – particles of soil and rock that are carried along in water

Nile Delta

Headland – an area of land that has water on 3 sides. Sandbar – sand that has been deposited over time so long that it makes a strip of sandy land.

Flood – when water collects on land that is normally dry Floodplain – place that is easily flooded when river water rises

Wind Erosion

Protecting Shorelines Breakwater – a long wall built out in the ocean parallel to the shore Fences and Dunes – help keep sand dunes from being eroded by the wind