4th Grade-Ch. 9 Lesson 2 How do weathered materials move

Ch. 9Lesson 2How do

weathered materials move?

erosion• process of moving weathered

rock by water, wind, ice & gravity

• creates canyons & valleys

•Waves constantly change the shape of the

shoreline.

Rivers can make deep canyons by erosion.

Grand Canyon

glacier•large ice sheet in cold place

•causes erosion

Glaciers

As a glacier melts, it wears away bits of rock and soil.

Glaciers [02:40]

deposition• laying down of pieces of

Earth’s surface• Builds up Earth’s surface

Weathering and Erosion YouTube video

creates deltas – fan shaped area of land

sand dunes

•rapid downhill movement of a large amount of rock & soil

- caused by gravity

landslide

landslide

avalanche• large amounts of snow & ice that fall rapidly down a mountain

Avalanche Control Team in Anchorage [03:34]

avalanche

ways to help reduce erosion

1. grow plants on hills to prevent erosion

ways to help reduce erosion

2. terracing- slows speed of rainfall

terracingbuilding of step like ridges in hilly areas to prevent water runoff

ways to help reduce erosion

3. build barriers to prevent waves

2 ways to stop erosion

of sand

1. jetty 2. sea wall

Fort Lauderdale beach sea wallFort Lauderdale beach sea wall

seawall

Activity- At the Beach• Problem: How do waves affect the beach?• Hypothesis: I predict that the waves will affect the

beach by _____. I predict that a jetty will help by _______.

• Procedure: 1. Shape sand into a beach.2. Pour water into side of pan opposite beach.3. Make waves with popsicle stick.4. Make beach again.5. Make a jetty by piling pebbles in a line in middle of

tray.6. Make waves with popsicle stick.• Observations:

Activity-Hills & Valleys

• Problem: How does moving water shape the

land ?

• Hypothesis: I predict that moving water (rain)

will cause the salt (mineral) to __________.

• Observations: _________________________

• Conclusion: ___________________________