Erosion and Weathering

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Slide 1

Erosion and Weathering

Slide 2

What is erosion?

(geology) the mechanical process of wearing or grinding something down (as by particles washing over it)

The wearing away of the earth’s surface by natural processes

corrosion: erosion by chemical action

Slide 3

Types of Erosion

Water

Wind

Glacier

Soil

Sea

Slide 4

Water

Occurs from chemicals in the water and the force and flow of water

Chemicals break down certain rocks like limestone or chalk

Force of water creates cracks and crevasses

These get bigger and bigger as it gets eroded, particles of the rock get carried in the water and further aid erosion

Slide 5

Wind

The wind picks up smaller particles of rock (pebbles and sand)

These hit landforms and take pieces off them

This friction causes the break up of landforms

Slide 6

Glacier Erosion

What is a GLACIER?:

A huge mass of ice slowly flowing over a land mass, formed from compacted snow in an area where snow accumulation exceeds melting

These large bodies of ice that pick up rocks and earth and erode the earth’s surface

Powerful eroding machine, picking up pieces of rock the size of houses in some places

Glaciers are so powerful they can carve valleys and create landforms

Slide 7

Sea Erosion

Salts and other chemicals in the water erode coastal rocks

These are dragged out to sea and deposited in other areas (Long shore Drift)

Wave power creates erosion. Also particles of rock and sediment aid to the erosion process

Slide 8

Soil Erosion

Biggest problem for farmers

Wind and rain remove topsoil and nutrients

Makes the soil infertile and it breaks up leaving dongas

Slide 9

Task

You are a forester in South Africa and you have just acquired some land and you are faced with a problem with soil erosion due to poor farming techniques:

YOUR PROBLEM:

DONGAS CASUED BY EROSION HAVE TAKEN UP CRITICAL SPACE FOR YOU TO PLANT AND GROW TREES

WHAT STEPS ARE YOU GOING TO TAKE TO REPAIR THE DONGAS?

WHAT IMPROVED PLANTING TECHNIQUES ARE YOU GOING TO USE?