Transcript Living Things - Lumio's Science World

Erosion and Deposition
Table of Contents
Changing Earth’s Surface
Water Erosion
The Force of Moving Water
Glaciers
Waves
Wind
Erosion and Deposition - Changing Earth’s Surface
Wearing Down and Building Up
Weathering, erosion, and deposition act together in a cycle
that wears down and builds up Earth’s surface.
Erosion and Deposition - Changing Earth’s Surface
Mass Movement
The different types of
mass movement
include landslides,
mudflows, slump, and
creep.
Erosion and Deposition - Changing Earth’s Surface
Mass Movement Activity
Click the Active Art button to open a browser window and
access Active Art about mass movement.
Erosion and Deposition - Changing Earth’s Surface
Comparing and Contrasting
As you read, compare and contrast the different types of
mass movement by completing a table like the one below.
Mass Movement
Type of Mass
Movement
Speed
Slope
Landslide
rapid
steep
Mudflow
rapid
gentle to steep
Slump
rapid
steep
Creep
slow
gentle to steep
Erosion and Deposition
Data Sharing Lab
Click the PHSchool.com button for an activity about sharing
data for the Skills Lab Sand Hills.
Erosion and Deposition
End of Section:
Changing Earth’s
Surface
Erosion and Deposition - Water Erosion
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.
Erosion and Deposition - Water Erosion
Runoff and Erosion
Water flowing across the land runs together to form rills,
gullies, and streams.
Erosion and Deposition - Water Erosion
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.
Erosion and Deposition - Water Erosion
Erosion by Rivers
Erosion often forms meanders and oxbow lakes where a
river winds across its floodplain.
Erosion and Deposition - Water Erosion
Deposits by Rivers
Deposition creates landforms such as alluvial fans and
deltas.
Erosion and Deposition - Water Erosion
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.
Erosion and Deposition - Water Erosion
Groundwater Erosion
Karst topography is found in many parts of the United States
where the bedrock is made up of thick layers of limestone.
Erosion and Deposition - Water Erosion
Groundwater Erosion
Chemical weathering of limestone and groundwater erosion
can create a limestone cave.
Erosion and Deposition - Water Erosion
Previewing Visuals
Before you read, preview Figure 10. Then write two
questions you have about the illustration in a graphic
organizer like the one below. As you read, answer your
questions.
The Course of a River
Q. What features does a river produce by erosion?
A. V-shaped valley, bluffs
Q. What feature does a river produce by deposition?
A. Delta
Erosion and Deposition - Water Erosion
More on Floods
Click the Planet Diary button for an activity about floods.
Erosion and Deposition
End of Section:
Water Erosion
Erosion and Deposition - The Force of Moving Water
How Water Erodes
Most sediment washes or falls into a river as a result of mass
movement and runoff. Other sediment erodes from the
bottom or sides of the river. Streams carry sediment in
several ways, as shown in the diagram.
Erosion and Deposition - The Force of Moving Water
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.
Erosion and Deposition - The Force of Moving Water
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.
Erosion and Deposition - The Force of Moving Water
Sediment on the Move
Reading Graphs:
What variable is shown on the
x-axis of the graph?
Stream velocity
Erosion and Deposition - The Force of Moving Water
Sediment on the Move
Reading Graphs:
What variable is shown on the
y-axis of the graph?
Diameter of sediment
particles
Erosion and Deposition - The Force of Moving Water
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
Erosion and Deposition - The Force of Moving Water
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
Erosion and Deposition - The Force of Moving Water
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.
Erosion and Deposition - The Force of Moving Water
Erosion and Sediment Load
A river erodes sediment from its banks on the outside curve
and deposits sediment on the inside curve.
Erosion and Deposition - The Force of Moving Water
Building Vocabulary
A definition states the meaning of a word or phrase by telling
about its most important feature or function. Carefully read
the definition of each Key Term and also read the
neighboring sentences. Then write a definition of each Key
Term in your own words.
Key Terms:
Examples:
energy
load
Energy
The
amount
is theofability
sediment
to dothat
work
a river
or cause
carries
change.
is its load.
friction
potential energy
Friction
the force
thatenergy
opposes
the
of one
Potentialisenergy
is the
that
is motion
stored and
surface
asbe
it moves
across another surface.
waiting to
used later.
Instead
moving
downstream,
water
moves
Kinetic of
energy
is the
energy anthe
object
has
due toever
its
which
motion.way in a type of movement called turbulence.
turbulence
kinetic energy
abrasion
Abrasion is the wearing away of rock by a grinding
action.
Erosion and Deposition - The Force of Moving Water
More on River Erosion
Click the PHSchool.com button for an activity
about river erosion.
Erosion and Deposition
End of Section:
The Force of
Moving Water
Erosion and Deposition - Glaciers
How Glaciers Form and Move
A continental glacier is a glacier that covers much of a
continent or large island.
Erosion and Deposition - Glaciers
How Glaciers Form and Move
During the last ice age, a continental glacier covered most of
northern North America.
Erosion and Deposition - Glaciers
How Glaciers Shape the Land
As a glacier moves, plucking breaks pieces of bedrock from
the ground.
Erosion and Deposition - Glaciers
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.
Erosion and Deposition - Glaciers
How Glaciers Shape the Land
As glaciers advance and retreat, they sculpt the landscape
by erosion and deposition.
Erosion and Deposition - Glaciers
Asking Questions
Before you read, preview the red headings. In a graphic
organizer like the one below, ask a what, how, or where
question for each heading. As you read, write answers to
your questions.
Question
Answer
What kinds of glaciers are
there?
Valley glaciers and
continental glaciers
How do glaciers shape
the land?
By erosion and deposition
Erosion and Deposition - Glaciers
Links on Glaciers
Click the SciLinks button for links on glaciers.
Erosion and Deposition
End of Section:
Glaciers
Erosion and Deposition - Waves
Erosion by Waves
Waves shape the coast through erosion by breaking down
rock and transporting sand and other sediment.
Erosion and Deposition - Waves
Erosion by Waves
Erosion and deposition create a variety of features along a
coast.
Erosion and Deposition - Waves
Deposits by Waves
Waves shape a coast when they deposit sediment, forming
coastal features such as beaches, spits, and barrier
beaches.
Erosion and Deposition - Waves
Identifying Main Ideas
As you read the section “Erosion by Waves,” write the main
idea in a graphic organizer like the one below. Then write
three supporting details that further explain the main idea.
Main Idea
Waves cause erosion by impact and by abrasion.
Detail
Energy in waves
breaks apart
rocks.
Detail
Sediment wears
away rock.
Detail
Landforms are
created.
Erosion and Deposition - Waves
Waves
Click the Video button to watch a movie about waves.
Erosion and Deposition - Waves
Links on Waves
Click the SciLinks button for links on waves.
Erosion and Deposition
End of Section:
Waves
Erosion and Deposition - Wind
How Wind Causes Erosion
Wind erosion moves sediment particles of different sizes in
the three ways shown below.
Erosion and Deposition - Wind
Wind Deposition
Wind erosion and deposition may form sand dunes and loess
deposits.
Erosion and Deposition - Wind
Sequencing
As you read, make a flowchart like the one below that shows
the process of wind erosion and deposition. Write each step
of the process in a separate box in the flowchart in the order
in which it occurs.
Wind Erosion
Wind picks up smallest particles of sediment.
Fine particles are carried through the air.
Medium-sized particles skip and bounce.
Larger particles slide or roll.
Erosion and Deposition
End of Section:
Wind
Erosion and Deposition
Graphic Organizer
Stream Formation
Raindrops strike ground.
Runoff forms.
Rills form.
Gullies form.
Gullies join together.
Stream forms.
Erosion and Deposition
End of Section:
Graphic Organizer