Transcript Weathering and Erosion

True or False: The Earth’s surface
has stayed the same for
thousands of years
True or False: The Earth’s surface
has stayed the same for thousands of
years
The Earth’s surface is always
changing!
Weathering
The breaking down of Earth’s crust into
smaller pieces.
Water causes weathering
What evidence of
weathering do you see
in this picture?
Wind causes weathering
Why wasn’t this mass
of land weathered
away?
What evidence of
weathering do you see
in this picture?
Ice causes weathering
Describe how ice
causes weathering?
How do we prove weathering takes place?
What are the 2 W’s that cause weathering?
• Each group will need a sugar cube (representing
a big rock), a pan, and a spray bottle.
• The whole class will use the two fans in the
classroom to represent wind.
• Each student will represent a “hurricane” (Don’t
be mistaken—light rain can also cause
weathering). Take turns to “rain” on the sugar
cube (the big rock). Each student (hurricane)
sprays on the sugar cube (big rock) for 30
seconds.
• What happened to the rock?
How do we prove moving water
causes weathering?
• What are examples of moving/running
water?
• Put a rock in a water bottle or jar.
• Shake the bottle for 2 minutes.
• What do you observe?
Let’s see more evidence of
weathering!
• Watch a brainpop.com video
about it.
• Read pages 136, 137 of your
book.
• We will go outside to look for
these proofs of weathering.
What is erosion?
• You will need a “rock”, “rain” (spray bottle),
Jenga blocks, and a tray.
• Groups 1, 2, 3,4, and 5 will tilt their tray by
using 0, 3, 6, 9, 12 blocks respectively.
• Spray or “rain” on the “rock”.
• Observe what happens to the loose
sediment.
Erosion
The process by which water, ice, or wind
moves fragments of rock and soil.
What evidence of
erosion do you see in
this picture?
Let’s show erosion caused by
ice.
• Let’s make a mixture of water and dirt.
• Freeze the mixture.
• What do you think will happen when we
take the frozen mixture of dirt and water
out of the freezer and put it outside at
normal room temperature?
Erosion is Movement of
Sediment!
• This process, known as
Erosion, is gradually
wearing down the
surface of the earth.
• Erosion is the process
by which weathered rock
and soil (sediment) are
moved from one place
to another.
• Erosion carves the
Earth's surface creating
canyons, gorges, and
even beaches.
What do you think has caused
this rock to look this way?
Wind Erosion
• As the wind blows it
picks up small
particles of
sand/sediment and
blasts large rocks
with the abrasive
particles, cutting and
shaping the rock.
Water Causes Erosion
• runoff, rivers and, streams
Water causes Erosion
When rain falls to the Earth
it can evaporate, sink into
the ground, or flow over
the land as Runoff.
When it flows over land,
erosion occurs.
Runoff picks up pieces of
rock and "runs" downhill
cutting tiny grooves
(called rills) into the land.
Ice Causes Erosion
Glaciers wear down the
landscape; by picking up and
carrying debris that moves
across the land along with
the ice.
Ice Causes Erosion
Glaciers can pick up and carry sediment that ranges in size
from sand grains to boulders bigger than houses.
Moving like a conveyor belt and a bulldozer, a single
glacier can move millions of tons of material!
How do we prevent erosion?
Plants CAN PREVENT erosion
Your turn!
• Read pp. 138
and 139
• Watch a video
on weathering
and erosion
• We will discuss the
questions from your
Study Guide.