Transcript Earth and Space Science Part 3

Earth and Space Science
Part 3
Abney Elementary
Mrs. Delaup/Ms. Martinez
• The Earth is always changing.
• Some of these changes are gradual
(slow) and some are rapid.
• Weathering and erosion are considered
gradual changes.
• Weathering takes place as rocks are broken
down into progressively smaller pieces by the
effects of weather. These pieces do not move
to a new location, they simply break down, but
remain next to one another.
• Erosion is the movement of rock particles
by water and wind. This often happens
when waves break on a beach; water
carries sand and other sediments as it
flows back into the ocean. Erosion along a
shore causes beaches to become smaller.
• Waves also deposit or drop sediments
near the shore. This is called
deposition.
Weathering and erosion of rock materials in Carlsbad
Caverns in New Mexico.
Sand is a product of erosion. Huge dunes have
accumulated in Colorado.
Sand carried by wind can blast through walls of rock
forming these arches in Utah
.
A deep V shaped river valley is cut into volcanic rocks
in Yellowstone National Park.
• Human activities, such as reducing
forest cover and intensive farming have
also changed the Earth’s surface.
• The Earth changes rapidly when
hurricanes, volcanoes, and
earthquakes occur.
• Strong gusty winds
blowing over and area
of many square miles
can cause a group of
very large waves called
a storm surge to form.
Storm surges often
occur during
hurricanes and can
cause a lot of damage
along a shore.
(Erosion)
• A volcano is a
mountain that
forms when redhot melted rock
flows through a
crack onto the
Earth’s surface.
• Volcanoes form when two plates collide,
when two plates separate, or when
plates move over hot spots in the
mantle.
• Melted rock inside Earth surface is
called magma.
• Melted rock that reaches Earth’s
surface is called lava.
• The magma flows onto the surface
through a rocky opening called a vent to
form volcanic mountains.
• The Earth changes
when volcanoes
produce new ocean
floor where plates are
moving apart.
Volcanic mountains
add to the continental
crust when they form
on land. They also
enrich the soil.
• Volcanoes can
also be harmful.
Lava and ash
often kill
everything in
their path.
Gases from the
eruption can also
be dangerous.
• An Earthquake is a vibration or shaking
of Earth’s crust.
• Earthquakes usually occur along faults.
• A fault is a break in
the crust along
which rock moves.
Rock on either side
of a fault can move
up and down, side to
side, or both.
• Earth’s crust and upper mantle are broken into
continent sized slabs called plates. Plates move
very slowly across Earth’s surface. (A few
centimeters a year)
• Plates can move toward each other, past
each other, or away from each other.
• Volcanoes or
mountains can occur
at places where
plates come
together.
• The island country of Iceland is the top
of an underwater mountain that formed
as ocean plates moved apart.
• Many earthquakes happen when plates
are moving past each other. This occurs
from the buildup and sudden release of
energy in rocks.
• The fault in
California
along which
dozens of
major
earthquakes
have occurred
is called the
San Andreas
Fault.
• Earthquakes can affect
the Earth by causing
tsunamis and mudslides
as well as changes the
Earth’s crust.
The End 