Download The Four Agents of Erosion

The Four Agents of Erosion
Finley’s 6th grade Science
Table of contents
How science works
Scientific Method
Science engineering and tech.
Chapter 1 review
Mineral Earth’s Jewels
Section 1 review
Igneous and Sedimentary
Metamorphic Rock
Rock Cycle
Chapter 3 Vocabulary
Do now Foldable
Section 1 homework
Erosion
Do Now 11/8/11
Glaciers
Do now 11/10/11
pg 1-2
pg 3-10
pg 9-12
pg 13
pg 15-20
pg 22
pg 23-28
pg29-32
pg 33-34
Pg 35
Pg 36
pg 37
pg 38-40
pg 41
pg 42-46
pg 45
Table of Contents
Wind erosion
pg 48
Do now
• Get a piece of colored paper
Step 1:Fold the piece of paper into 3rds
(like a brochure)
Step 2: while the paper is folded up fold it again into
fourths
fold the (brochure like) in half hamburger style
Then open it back up and fold each end to the middle.
Step 3: Unfold the whole thing and trace the lines along
the folds
Label your table
Do Now Foldable pg 36
Erosional Forces
Erosion
Deposition
Gravity
Glacier
Wind
As we go through the chapter complete the chart , listing specific examples of
Erosion and deposition for each erosional force.
Vocabulary on pg 35
• Erosion- is a process that wears away surface materials and
moves them from one place to another
• Deposition- when agents of erosion drop sediments they
are carrying as they lose energy
• Mass Movement- is any type of erosion that happens as
gravity moves materials downslope
• Slump- When a mass of material slips down along a curved
surface
• Creep – occurs when sediments slowly shift their positions
down hill ex: leaning trees
• Rockfalls/ Rock Slides- happen when blocks of rocks break
loose and tumble through the air.
Vocabulary pg 35
• Mudflows- occur in areas that have thick
layers of loose sediments. Mudflow occur
after heavy rain and gravity causes the mass
to flow downhill.
Erosions by gravity pg 38
• What wears away
Sediments?
• Gravity is the force of
attraction that pulls all
objects towards Earth.
• Water & wind erode
materials only when they
have enough energy of
motion to do work.
• Ex: air can’t move much
sediments on a calm day,
but on a strong wind can
move dust and even
larger particles.
Mass Movement pg 38
• How does gravity aid in
mass movement?
• Gravity is constantly
pulling object towards
Earth. So as long as
there is gravity objects
will continue to fall and
erode in mass
movement.
Mass Movement pg 38
• What are the common
types of mass
movement?
• Slump, creep, rockfalls,
rock slides, mudslides,
landslides
Mass movements pg 38
• What conditions are
favorable for triggering
mudflows?
• A normally dry area,
with thick layers of dry
sediments and
vegetation removed by
fire or other means,
suddenly experiences a
heavy rainfall.
Be Prepared to take notes!!!
Consequences of Erosion pg 40
• How do people affect
the rate at which
erosion occurs?
• People like to build on
the side of steep slopes.
In order to do this they
must excavate the dirt
and vegetation. This
speeds up erosion
causing additional
problems for people.
Consequences of Erosion pg 40
• How can people slow
down erosion and make
the sloped a safer place
to build on?
• One of the best ways to
reduce erosion is to
plant vegetation and
trees with deep roots.
This helps to hold the
soil in place. People can
also build concrete
retaining walls.
Do now pg 41
Write down what you think of when you hear
the word glacier. Describe what a glacier looks
like and how it moves.
Glaciers
Glaciers pg 42
How do glacier form and
move?
When snow doesn’t melt it
piles up. As it piles up
slowly, the weight of the
snow gets greater. The
snow begins to press the
layers into ice. Once there
is enough pressure it
becomes like plastic. The
plasticlike ice starts to
move from where it was
formed.
Glaciers pg 42
• How does a glacier
cause erosion?
• Glaciers erode land and
change the surface.
They act like a giant
bulldozer. They scrape
up soil, rocks, and
plants and carry them
along.
Glaciers pg 42
• What is plucking?
• Plucking is the action in
which a moving glacier
picks up loose pieces of
rock.
Glacier pg 42
• What is transporting
and scouring?
• A glacier carries huge
amounts of sediment
and rock as it moves.
The action of carrying
sediment and rock is
called transporting.
• When moving glaciers
scour the bedrock, they
leave marks on it.
Glaciers pg 44
• What types of marks do
glaciers leave?
• Glaciers leave Striations
and grooves.
• What is the difference
between Striations and
grooves.
• Striations are shallow
marks.
• Grooves are long, deep,
side-by-side scars.
Grooves & Striation
Grooves
Striation
Glaciers pg 44
• What is till?
Till is the mix of different
sized sediments that are
deposited from a
retreating glacier.
Glaciers pg 44
• What are moraine
deposits?
• Rocks and soil are
moved to the end of
glacier. As a result, a big
ridge of soil and rocks
pile up. This deposit is
called a moraine.
Glaciers pg 46
• What is an outwash?
• What are eskers?
An outwash is the
material deposited by
the water from a
melting glacier.
An esker is a meltwater
stream inside the
glaciers ice.
Eskers
Do now 11/10/11 pg 45
Identify- name two kinds of marks that glaciers
leave in a rock?
Think about a windy day when dust or sand was
blown in your face. Write about how it felt.
Left over Esker from a glacier
Glacier pg 46
What are the two types of
glaciers?
The two types of glaciers
are continental glaciers
and valley glaciers.
What is the difference
between Continental
and valley glaciers?
Continental glaciers are
wide, thick sheet of ice
and snow. They cover
huge areas of land.
Valley glaciers are found in
high mountain ranges.
Glacier’s pg 46
• Identify some states
that were once covered
by a glacier.
Glaciers pg 46
• What are the signs that
valley glaciers existed?
1. Look for grooves in the
rock.
2. Look for signs of plucking
3. Bowl shaped basins called
cirques.
4. If the mountain was
eroded from many
directions it can form a
horn.
5. An arete which is a ridge
where two glaciers have
eroded side-by-side
Valley Glaciers
Wind Erosion pg 48
What is wind erosion?
Erosion is the process that
wears away surface
materials and moves
them from one place to
another.
When air moves, it picks
up tiny bits of loose
material. Air is different
then Gravity or glaciers
in that it cannot pick up
heavy sediments.
Wind pg 48
• How does deflation
erode the land?
• Deflation is erosion that
occurs when wind
removes small
sediments, such as silt
and sand, leaving
behind large sediments.
Wind Erosion pg 48
• How does abrasion
erode the land?
Just as a sandblaster
sprays a mix of sand
and water to clean and
polish materials.
Abrasion scrapes and
wears away rock pieces
leaving them pitted,
polished, and worn
down.
Wind erosion pg 48
• Where so deflation and
abrasion occur most
often?
Deflation and abrasion
occur most at beaches,
deserts, and plowed
fields.
Wind erosion pg 50
• What are sandstorms?
When strong winds blow
in a sandy desert, the
sand grains raise into
the air. The blowing
sand forms a cloud just
above the ground.
Wind pg 50
• What causes a dust
storm?
Dust storms are clouds of
fine particles of soil
blown by wind. Dust
storms can cover
hundreds of kilometers.
Dust Bowl
Reducing wind erosion pg 50
How do we reduce wind
erosion?
People plant vegetation to
stop wind erosion.
These are called wind
breaks. As wind hits the
trees it slows down the
wind.
Deposition of Wind pg 50
• What does the
deposited sediments
from wind form?
• Over time, some of the
sediments develop into
landforms such as
dunes and loess.
Wind Deposition
Dune
Loess
Wind Deposition pg 52
What is a loess?
Loess are wind deposits of
fine grained sediments.
The sediments pack
together creating a
thick, un-layered,
yellow and brown in
color.
Wind deposition pg 52
What are dunes?
Dunes happen when wind
blows sediments against
an obstacle such as a rock
or vegetation.
How do dunes move?
A sand dune has two sides.
The side facing the slope
which has a gentle slope,
and the side away from
the wind which is steeper.
The dunes move in the
direction away from the
wind.
Wind deposition pg 52
Dune shapes
Barchan dunecrescent shaped
Transverse DuneDunes are
perpendicular to
the wind
direction