4th grade ch 9 lesson 2 how do weathered materials move
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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 glacier melts wears away bits of rock & 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
seawall
2 ways to stop erosion
of sand
1. jetty 2. sea wall
Fort Lauderdale beach sea wallFort Lauderdale beach sea wall
Activity- At the Beach• Problem: How can I prevent waves from eroding a
beach?• Hypothesis: I predict that the waves will affect the
beach by _____. • Procedure: 1. Shape sand into a beach.2. Pour water into side of pan opposite the beach.3. Make waves with a 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: ___________________________