Chapter 3 Erosion and Deposition

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Chapter 3 Erosion and Deposition
Table of Contents
Chapter Preview
3.1 Changing Earth’s Surface
3.2 Water Erosion
3.3 Waves and Wind
3.4 Glaciers
Chapter 3 Erosion and Deposition
Chapter Preview Questions
1. The process that breaks down rock and other substances
at Earth’s surface is called
a. uniformitarianism.
b. weathering.
c. mountain building.
d. erosion.
Chapter 3 Erosion and Deposition
Chapter Preview Questions
1. The process that breaks down rock and other substances
at Earth’s surface is called
a. uniformitarianism.
b. weathering.
c. mountain building.
d. erosion.
Chapter 3 Erosion and Deposition
Chapter Preview Questions
2. What is the term for the mixture of rock particles, minerals,
decayed organic material, water, and air?
a. bedrock
b. humus
c. loam
d. soil
Chapter 3 Erosion and Deposition
Chapter Preview Questions
2. What is the term for the mixture of rock particles, minerals,
decayed organic material, water, and air?
a. bedrock
b. humus
c. loam
d. soil
Chapter 3 Erosion and Deposition
Chapter Preview Questions
3. Which of the following is a cause of mechanical weathering?
a. abrasion
b. oxygen
c. acid rain
d. living organisms
Chapter 3 Erosion and Deposition
Chapter Preview Questions
3. Which of the following is a cause of mechanical weathering?
a. abrasion
b. oxygen
c. acid rain
d. living organisms
Chapter 3 Erosion and Deposition
Chapter Preview Questions
4. Conservation plowing, crop rotation, and contour plowing
are methods of promoting
a. soil loss.
b. soil conservation.
c. loss of fertility.
d. loss of topsoil.
Chapter 3 Erosion and Deposition
Chapter Preview Questions
4. Conservation plowing, crop rotation, and contour plowing
are methods of promoting
a. soil loss.
b. soil conservation.
c. loss of fertility.
d. loss of topsoil.
Chapter 3 Erosion and Deposition
What are the forces of erosion and deposition that
shape our landscape?
Suppose that you fill a jar halfway
with layers of gravel, sand, and
soil. Then you fill the jar with
water, cover it tightly, and shake
for 5 seconds. What effect would
shaking the jar have on the soil,
sand, and gravel? What would
happen to them after the shaking
stops? Explain your answer.
Chapter 3 Erosion and Deposition
Latin Word Origins
Word
de-
Meaning
Examples
From, down, away
Deflation, deposition
Chapter 3 Erosion and Deposition
Latin Word Origins
Word
flare
Meaning
Examples
Blow
Deflation
Chapter 3 Erosion and Deposition
Latin Word Origins
Word
-mentum
Meaning
The act of, the result of
Examples
Movement
Chapter 3 Erosion and Deposition
Latin Word Origins
Word
positus
Meaning
Put
Examples
Deposition
Chapter 3 Erosion and Deposition
Latin Word Origins
Word
sedere
Meaning
Examples
Sit, settle
Sediment
Chapter 3 Erosion and Deposition
Apply It!
Review the Latin words and meanings. Look at the word sedere
and the second meaning of mentum. Predict the meaning of
sediment. Revise your definition as you read the chapter.
Sample: Sedere means “settle” and mentum means “the result of.”
Chapter 3 Erosion and Deposition
End of Chapter
Preview
Chapter 3 Erosion and Deposition
Section 1:
Changing Earth’s Surface
What processes wear down and build up
Earth’s surface?
What causes the different types of mass
movement?
Chapter 3 Erosion and Deposition
Wearing Down and Building Up
Weathering, erosion, and deposition act together in a cycle
that wears down and builds up Earth’s surface.
Chapter 3 Erosion and Deposition
Mass Movement
The different types of
mass movement
include landslides,
mudflows, slump, and
creep.
Chapter 3 Erosion and Deposition
Mass Movement Activity
Click the Active Art button to open a browser window and
access Active Art about mass movement.
Chapter 3 Erosion and Deposition
End of Section:
Changing Earth’s
Surface
Chapter 3 Erosion and Deposition
Section 2:
Water Erosion
What process is mainly responsible for
shaping the surface of the land?
What features are formed by water erosion
and deposition?
What factors affect a river’s ability to erode
and carry sediment?
Chapter 3 Erosion and Deposition
Sediment in Motion
Streams carry sediment in several ways.
Chapter 3 Erosion and Deposition
Runoff and Erosion
Precipitation over the United States averages about 75 cm
per year. About 22.5 cm becomes runoff. Generally, more
runoff means more erosion.
Chapter 3 Erosion and Deposition
Runoff and Erosion
Water flowing across the land runs together to form rills,
gullies, and streams.
Chapter 3 Erosion and Deposition
Erosion by Rivers
A waterfall forms where a flat layer of tough rock lies over a
layer of softer rock that erodes easily. When the softer rock
erodes, pieces of the harder rock above break off, creating
the waterfall’s sharp drop.
Chapter 3 Erosion and Deposition
Erosion by Rivers
Erosion often forms meanders and oxbow lakes where a
river winds across its floodplain.
Chapter 3 Erosion and Deposition
Deposits by Rivers
Deposition creates landforms such as alluvial fans and
deltas.
Chapter 3 Erosion and Deposition
The Course of a River
The slope and size of a
river, as well as the
sediment it carries,
determine how a river
shapes the land.
Chapter 3 Erosion and Deposition
The Course of a River
The slope and size of a
river, as well as the
sediment it carries,
determine how a river
shapes the land.
Chapter 3 Erosion and Deposition
Erosion and Sediment Load
A river’s slope is usually greatest near the river’s source.
As a river approaches its mouth, its slope lessens.
Chapter 3 Erosion and Deposition
Sediment on the Move
The speed, or velocity, of a
stream affects the size of the
sediment particles the stream
can carry. Study the graph, then
answer the following questions.
Chapter 3 Erosion and Deposition
Sediment on the Move
Reading Graphs:
What variable is shown on
the x-axis of the graph?
Stream velocity
Chapter 3 Erosion and Deposition
Sediment on the Move
Reading Graphs:
What variable is shown on the
y-axis of the graph?
Diameter of sediment
particles
Chapter 3 Erosion and Deposition
Sediment on the Move
Interpreting Data:
What is the speed at which a
stream can move coarse
sand? Small pebbles? Large
boulders?
About 50 cm/sec; about 90
cm/sec; about 800 cm/sec
Chapter 3 Erosion and Deposition
Sediment on the Move
Predicting:
A stream’s speed increases to
about 600 cm per second
during a flood. What are the
largest particles the stream
can move?
Small boulders
Chapter 3 Erosion and Deposition
Sediment on the Move
Developing Hypotheses:
Write a hypothesis that states
the relationship between the
speed of a stream and the
size of sediment particles it
can move.
The faster the speed of the
flowing water, the larger the
particles the stream is able to
move.
Chapter 3 Erosion and Deposition
Erosion and Sediment Load
A river erodes sediment from its banks on the outside curve
and deposits sediment on the inside curve.
Chapter 3 Erosion and Deposition
More on Floods
Click the Planet Diary button for an activity about floods.
Chapter 3 Erosion and Deposition
End of Section:
Water Erosion
Chapter 3 Erosion and Deposition
Section 3:
Waves and Wind
What gives waves their energy?
How do waves shape a coast?
What are the causes and effects of wind erosion?
Chapter 3 Erosion and Deposition
Erosion by Waves
Waves shape the coast through erosion by breaking down
rock and transporting sand and other sediment.
Chapter 3 Erosion and Deposition
Erosion by Waves
Erosion and deposition create a variety of features along a
coast.
Chapter 3 Erosion and Deposition
Deposits by Waves
Waves shape a coast when they deposit sediment, forming
coastal features such as beaches, spits, and barrier
beaches.
Chapter 3 Erosion and Deposition
How Wind Causes Erosion
Wind erosion moves sediment particles of different sizes in
the three ways shown below.
Chapter 3 Erosion and Deposition
Wind Deposition
Wind erosion and deposition may form sand dunes and loess
deposits.
Chapter 3 Erosion and Deposition
Links on Waves
Click the SciLinks button for links on waves.
Chapter 3 Erosion and Deposition
Waves
Click the Video button to watch a movie about waves.
Chapter 3 Erosion and Deposition
End of Section:
Waves and Wind
Chapter 3 Erosion and Deposition
Section 4:
Glaciers
What are the two kinds of glaciers?
How does a valley glacier form and move?
How do glaciers cause erosion and deposition?
Chapter 3 Erosion and Deposition
How Glaciers Form and Move
During the last ice age, a continental glacier covered most of
northern North America.
Chapter 3 Erosion and Deposition
How Glaciers Shape the Land
As a glacier moves, plucking breaks pieces of bedrock from
the ground.
Chapter 3 Erosion and Deposition
How Glaciers Shape the Land
Erosion by glaciers can carve a mountain peak into a sharp
horn and grind out a V-shaped valley to form a U-shaped
valley.
Chapter 3 Erosion and Deposition
How Glaciers Shape the Land
As glaciers advance and retreat, they sculpt the landscape
by erosion and deposition.
Chapter 3 Erosion and Deposition
Links on Glaciers
Click the SciLinks button for links on glaciers.
Chapter 3 Erosion and Deposition
End of Section:
Glaciers
Chapter 3 Erosion and Deposition
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