1. Changes to the Earth's Surface
GEOLOGY
Changes to the Earth's Surface
SOL 5.7
K. Benzie
CSES

2. Changes to the Earth's Surface
Forces are constantly changing landforms. Some of the forces
that change landforms are:
1. flowing water, such as rivers and ocean waves
2. wind
3. ice and glaciers
4. force of gravity
Weathering is the process of breaking rock into silt, sand, clay,
and other tiny pieces called sediments.

3. Physical Weathering
Weathering can be from the physical breaking up of the earth's
surface. Examples of physical weathering are:
1. when water freezes in cracks and then thaws
2. from water; either rain, flowing water as in rivers and
streams, or from ocean waters pounding against the shore
3. when people farm or build roads, etc.
4. when wind blows dirt and sand against rocks

4. Chemical Weathering
Chemical weathering changes the minerals that make up rock.
For example, water and oxygen cause rust to form on certain
minerals in rocks, causing the rocks to crumble. Pollutants in
the air can create acid rain which erodes. Rain mixes with
carbon dioxide to form an acid which creates caves.

5. Biological Weathering
Biological weathering is changes caused by living things:
1. when roots of plants break up the earth
2. when animals, such as earthworms and prairie dogs,
build tunnels

6. Weathering Let's review:
Weathering is constantly changing the landforms around us.
Weathering is caused by water, wind, ice, gravity, and
changes in temperature.
There are three types of weathering: physical, chemical
and biological.

7. Weathering
Don't confuse weathering with erosion!
Weathering breaks up the Earth's surface into small pieces
called sediment. Erosion is the process of moving sediments
from one place to another. Deposition is the process of
dropping, or depositing, sediments in new locations.
Weathering Erosion Deposition
Wind, water, gravity, and
humans are all causes of erosion.