unit 5 weather, erosion & deposition what is weathering? how does it effect objects? weathering...

Unit 5 Weather, Erosion & Deposition

What is weathering? How does it effect objects?

Weathering notes

This unit you will learn1. What is and what are the factors of weathering.2. What is and what are the factors of erosion.3. What is and what are the factors of deposition.4. The difference between soil and dirt! Yes there is

one.5. Types of weathering, erosion & deposition.6. Mass movements7. Glaciers8. Rivers9. Landscape regions

Much of this unit is review?!• So, let’s try to use this unit to get your grade

up before the last few units of the year.

Definitions for the day

• Weathering– Chemical weathering– Physical weathering

• Surface area• Abrasion• Frost action• Root Pry• Oxidation

Weathering

• The process of breaking down material.• Occurs naturally when exposed to the elements

(like wind, water, plants and animals)

Exposure• Exposure to:– Wind– Rain, Sleet, Snow– Biologic activity

• How does this affect weathering

Weathering rates?• Depends on how hard or resistant the material is• Surface area- the amount of area available to be

weathered.• If we increase the surface area what will happen

to the amount of potential weathered area?

Let’s try?!• SA=L x W x # of sides– L-Length– W-Width

• 4 cm * 4 cm * 6 sides • SA= 96 sq cm

4 cm

4 cm

4 cm

You try

• SA=____x___x____

• SA=2 * 2 * 6 • SA= 24 sq cm

2 cm

2 cm

2 cm

Now what?

• What if we cut the cube in half?

• OLD SA= 24 sq cm

• NEW SA= ???– SA= 1 * 1 * 48 sides– SA= 48 sq cm

• INCREASE SA = Decrease in size!!

2 cm

2 cm

2 cm

1 cm 1 cm

1 cm

Physical Weathering

• Changing the shape and or size of an object without changing the chemical make up.

• Types– Frost action• Water seeps into cracks and freezes pushing open crack

as it expands.

– Abrasion• When two objects collide

– Exfoliation

Chemical Weathering

• Changing the chemical makeup of a material.• Types

• Oxidation• Hydration• Carbonation

Take note

• Chemical – End does not equal the same thing as the beginning!

• Physical- End same as beginning!

So, if something has undergone physical weathering then the ending object is the same chemically as the beginning. If an object has been chemically weathered then the end object is different from the beginning object.

You try!

• A rock hitting another rock? C or P• A pot hole? C or P• A rock with a red coloring? C or P• A bonfire? C or P• A tree with roots in the bed rock? C or P• Hitting a hammer on a rock? C or P• Putting a tooth in a cup of Pepsi? C or P

P

P

P

P

CC

C