How do weathering and erosion shape the land?

UNIT C:

CHAPTER 5: LESSON 5:

Weathering

The process in which rocks or other materials are broken down.

Different types of weathering:

Physical weathering Chemical weathering

Physical Weathering:

Physical weathering is caused by:

1) Temperature changes (Causes rocks to crack)

2) Plant roots growing in rocks breaking the rocks.

3) Water freezing in cracks between rocks cause the rocks to break apart.

4) Rubbing

5) Animals making burrows.

Chemical Weathering:

Occurs when chemicals break down the rocks.

1) Water dissolves rocks.

The agents of chemical weathering:

2) Acid Rain

Formed when gases from factories combine with rain water.

Erosion

The process by which water, ice, wind or gravity moves fragments of rock and soil.

If a particle is loosened by weathering, but stays put, its just weathering.

If it starts moving, its Erosion.

Water Erosion

Rivers, streams, and runoff

Ice Erosion

Glaciers

Wind Erosion

Mass Movements

Landslides, mudslides, slump and creep

Get out a piece of paper and identify if the following involve

weathering, erosion, both, or neither.

Ready?

1.Waves are crashing on a sand beach.

2.Water expands as it freezes in the cracks of rocks.

3. Pebbles move down a stream with the current.

4. Acid rain causes the decomposition of a statue in New York.

5. A man shovels dirt to plant a tree.

6. A Glacier slowly moves down a mountain.

7. A tree’s roots grow into the cracks of rocks.

8. A major volcano erupts.

9. A boy takes out the garbage for his mother.

10. A shovel is left outside and begins to rust.

Once you’ve answered these, discuss you’re

answers with the rest of the class before you go on.

Let’s Discuss The Questions.

1. As the sand is moving there is definitely erosion; there is also abrasion from the sand gains colliding. Both

2. This is frost wedging so it’s mechanical weathering. There is no mention of movement. Weathering

3. There is probably some weathering, but there is definitely erosion. Erosion or Both

4. Acid rain on a statue is chemical weathering. This is mainly Weathering.

5. Since the man is transporting Earth materials, it’s Erosion.

6. A glacier moving down a mountain would have both weathering and erosion. Both

7. A tree’s roots growing into cracks of rocks would be weathering. Weathering

8. A major volcanic eruption would involve both weathering and erosion. Both

9. Unless the garbage has “Earth Material” or dirt in it there is probably no erosion or weathering. Neither

10. The rusting of a shovel is oxidation. This is chemical weathering. Weathering

The process by which materials are dropped off at another place is called:

Deposition

Erosion and deposition work

together to change the shape of the earth’s surface.

Ways that erosion and deposition work together:

1) Running water

Slow moving water Deposition

Fast moving water Erosion

2) Waves

HeadlandLand surrounded by water from 3 sides.

When waves reach a headland they curve around it and wash away at

the sides of the headland.

3) Wind

Wind erodes sand and rock, when the wind slows down the sand

and rock get deposited.

How can people protect shorelines?

Shorelines may be damaged when more sand is eroded than deposited.

People can protect shorelines by:1) Building dams (to change the speed and

direction of water)

2) Building levees (prevent floods)

3) Building barricades (prevent beach erosion)

4) Building fences (prevent sand erosion by wind)