Landscape Changes October 9 th, 2009

Processes that help change the Landscape Over the course of geological history, several processes have helped to shape the land The land around us is constantly being built or destroyed / changed There are THREE main processes: – Erosion – Weathering – Deposition

Erosion Erosion is the displacement (movement) of solids, like rock, by the agents of ocean currents, wind, water, or ice by downward movement Basically it’s the wearing away of the earth’s surface by natural causes in combination with gravity Examples of erosion landforms: – Valleys, striations, grooves, bays

Loch End Gorge, Australia

12 Apostles, Australia

Weathering Weathering occurs without movement Mechanical or physical weathering is the breakdown of rocks and soils through direct contact with atmospheric conditions such as heat, water, ice and pressure (i.e. freezing / thawing) Chemical or biological weathering involves the direct effect of atmospheric chemicals, or biologically produced chemicals in the breakdown of rocks, soils and minerals (i.e. acid rain)

Freeze / Thaw Process

Hoodoos – Drumheller, Alberta

Chemical Weathering

Biological / Chemical Weathering - oxidized iron, chemicals in the rain and rocks reacting - tree roots entering the cracks in the rocks and splitting the rock

Video Clip

Deposition Also known as sedimentation Process where material is added to a landform Wind, water or ice create a sediment deposit, through the layering down of material that has been eroded and transported from one location to another Examples of depositional landforms are: – Beaches, soil drumlins, eskers, till deposits and moraines

Drumlin

Drumlin – Side View

Esker

Glacial Till

Quiz!!!!

What process helped shape me?

What process caused this damage to the statute?

What was the main process that helped form this landscape?