Transcript Natural forces move and deposit sediments
Slide 1
Forces wear down and
build up earth’s surface
5.1 notes
Slide 2
Think about…
How did natural forces shape
this landform?
Slide 3
Natural forces move and deposit
sediments
Valleys and canyons are formed
by the movement of water.
Slide 4
Natural forces move and
deposit sediments
The process in
which weathered
particles are
picked up and
moved from one
place to another
is called erosion.
Slide 5
Natural forces move and
deposit sediments
The part of the
erosion process in
which sediment is
placed in a new
location
(deposited) is
called deposition.
Slide 6
Natural forces move and
deposit sediments
The force of gravity is an important
part of erosion and deposition.
Slide 7
Natural forces move and
deposit sediments
Gravity causes water to move
downward, carrying and depositing
sediment as it flows.
Slide 8
Natural forces move and
deposit sediments
Gravity can pull huge masses of ice
slowly down mountain valleys.
Slide 9
Natural forces move and
deposit sediments
Gravity causes dust carried by the wind
to fall to Earth.
Slide 10
Natural forces move and
deposit sediments
Erosion of weathered rock
by movement occurs in 3
major ways:
Slide 11
Natural forces move and
deposit sediments
1. Water
Rainwater and melting snow carry
rock and soil particles down
sloping land, eventually depositing
them on river bottoms and
riverbanks.
Slide 12
Natural forces move and
deposit sediments
oWaves in oceans and lakes
also carry sediment and
deposit it to form beaches and
other features.
Slide 13
Natural forces move and
deposit sediments
2. Wind
Strong winds lift tiny particles
of dust and carry them long
distances.
When the wind dies down,
the particles drop to the
ground.
Slide 14
Natural forces move and
deposit sediments
3. Ice
As ice moves slowly
downhill, it transports rock
and soil particles that are
embedded in it.
Slide 15
Gravity can move large amounts
of rock and soil
Many homes can
be found along
the beautiful cliffs
of coastal
California.
Why might this be
a risky place to
build a house?
Slide 16
Gravity can move large
amounts of rock and soil.
Many coastal and mountainous regions have
landslides.
A landslide is a type of mass wasting-the
downhill movements of masses of rock and soil.
Slide 17
Gravity can move large
amounts of rock and soil.
In mass wasting,
gravity pulls material
downward.
There is often a
trigger event, such as
heavy rain or an
earthquake.
Slide 18
Gravity can move large
amounts of rock and soil.
Mass wasting can occur suddenly or
gradually.
It can involve tons of rock sliding quickly
or gradually moving a little at a time.
Slide 19
Gravity can move large
amounts of rock and soil.
Mass wasting can be classified by
the type of material that is moved
and the speed at which it is
moved.
Slide 20
Gravity can move large
amounts of rock and soil.
A sudden, fast, movement of
rock and soil is called a
landslide.
Slide 21
Gravity can move large
amounts of rock and soil.
Movement of mud or soil is
described as a mudflow.
Slide 22
Mass wasting of rock
Mass wasting of rock
includes rockfalls and
rockslides.
Slide 23
Mass wasting of rock
A rockfall is when individual blocks of
rock drop suddenly and fall freely down
a cliff or steep mountainside.
Slide 24
Mass wasting of rock
A rockslide is when a large mass of rock
slides as a unit down a slope.
Rockslides can reach speeds of 100
km/hr!
Slide 25
Mudflow
A mudflow is the mass wasting of debris with
large amounts of water.
Debris is a mixture of rock, soil, and plants.
Slide 26
Mudflow
Mudflows often happen
in canyons and valleys
after heavy rains.
The soil becomes so
heavy that the slope
can no longer hold it in
place.
Slide 27
Mudflow
Mudflows also occur on active
volcanoes.
Slide 28
Mudflow
In 1985, a huge mudflow caused by a
volcano destroyed the town of Armero,
Colombia, and killed more than 20,000
people.
Slide 29
Mudflow
The eruption of Mt. St. Helens in 1980
caused mudflows that traveled more than
90 km from the mountain!
Slide 30
Slumps and creep
A slump is a slide of
loose debris that
moves as a single unit.
Slumps can occur
along roads and
highways where
construction has made
slopes unstable.
Slide 31
Slumps and creep
Creeps are the slowest
form of mass
movement.
The soil or debris
moves at a rate of 1-10
mm per year-too slow
to be directly
observed.
Slide 32
Slumps and creep
Creep can affect
buildings as wellsometimes enough
to crack walls!
The wetter the soil,
the faster it will
creep.
Slide 33
Review
1. The main natural force
responsible for mass movements of
rocks and debris is
A. rainwater
B. wind
C. gravity
D. fire
Forces wear down and
build up earth’s surface
5.1 notes
Slide 2
Think about…
How did natural forces shape
this landform?
Slide 3
Natural forces move and deposit
sediments
Valleys and canyons are formed
by the movement of water.
Slide 4
Natural forces move and
deposit sediments
The process in
which weathered
particles are
picked up and
moved from one
place to another
is called erosion.
Slide 5
Natural forces move and
deposit sediments
The part of the
erosion process in
which sediment is
placed in a new
location
(deposited) is
called deposition.
Slide 6
Natural forces move and
deposit sediments
The force of gravity is an important
part of erosion and deposition.
Slide 7
Natural forces move and
deposit sediments
Gravity causes water to move
downward, carrying and depositing
sediment as it flows.
Slide 8
Natural forces move and
deposit sediments
Gravity can pull huge masses of ice
slowly down mountain valleys.
Slide 9
Natural forces move and
deposit sediments
Gravity causes dust carried by the wind
to fall to Earth.
Slide 10
Natural forces move and
deposit sediments
Erosion of weathered rock
by movement occurs in 3
major ways:
Slide 11
Natural forces move and
deposit sediments
1. Water
Rainwater and melting snow carry
rock and soil particles down
sloping land, eventually depositing
them on river bottoms and
riverbanks.
Slide 12
Natural forces move and
deposit sediments
oWaves in oceans and lakes
also carry sediment and
deposit it to form beaches and
other features.
Slide 13
Natural forces move and
deposit sediments
2. Wind
Strong winds lift tiny particles
of dust and carry them long
distances.
When the wind dies down,
the particles drop to the
ground.
Slide 14
Natural forces move and
deposit sediments
3. Ice
As ice moves slowly
downhill, it transports rock
and soil particles that are
embedded in it.
Slide 15
Gravity can move large amounts
of rock and soil
Many homes can
be found along
the beautiful cliffs
of coastal
California.
Why might this be
a risky place to
build a house?
Slide 16
Gravity can move large
amounts of rock and soil.
Many coastal and mountainous regions have
landslides.
A landslide is a type of mass wasting-the
downhill movements of masses of rock and soil.
Slide 17
Gravity can move large
amounts of rock and soil.
In mass wasting,
gravity pulls material
downward.
There is often a
trigger event, such as
heavy rain or an
earthquake.
Slide 18
Gravity can move large
amounts of rock and soil.
Mass wasting can occur suddenly or
gradually.
It can involve tons of rock sliding quickly
or gradually moving a little at a time.
Slide 19
Gravity can move large
amounts of rock and soil.
Mass wasting can be classified by
the type of material that is moved
and the speed at which it is
moved.
Slide 20
Gravity can move large
amounts of rock and soil.
A sudden, fast, movement of
rock and soil is called a
landslide.
Slide 21
Gravity can move large
amounts of rock and soil.
Movement of mud or soil is
described as a mudflow.
Slide 22
Mass wasting of rock
Mass wasting of rock
includes rockfalls and
rockslides.
Slide 23
Mass wasting of rock
A rockfall is when individual blocks of
rock drop suddenly and fall freely down
a cliff or steep mountainside.
Slide 24
Mass wasting of rock
A rockslide is when a large mass of rock
slides as a unit down a slope.
Rockslides can reach speeds of 100
km/hr!
Slide 25
Mudflow
A mudflow is the mass wasting of debris with
large amounts of water.
Debris is a mixture of rock, soil, and plants.
Slide 26
Mudflow
Mudflows often happen
in canyons and valleys
after heavy rains.
The soil becomes so
heavy that the slope
can no longer hold it in
place.
Slide 27
Mudflow
Mudflows also occur on active
volcanoes.
Slide 28
Mudflow
In 1985, a huge mudflow caused by a
volcano destroyed the town of Armero,
Colombia, and killed more than 20,000
people.
Slide 29
Mudflow
The eruption of Mt. St. Helens in 1980
caused mudflows that traveled more than
90 km from the mountain!
Slide 30
Slumps and creep
A slump is a slide of
loose debris that
moves as a single unit.
Slumps can occur
along roads and
highways where
construction has made
slopes unstable.
Slide 31
Slumps and creep
Creeps are the slowest
form of mass
movement.
The soil or debris
moves at a rate of 1-10
mm per year-too slow
to be directly
observed.
Slide 32
Slumps and creep
Creep can affect
buildings as wellsometimes enough
to crack walls!
The wetter the soil,
the faster it will
creep.
Slide 33
Review
1. The main natural force
responsible for mass movements of
rocks and debris is
A. rainwater
B. wind
C. gravity
D. fire