Download The Earth*s Physical Geography

Forces Shaping Earth 2-2
Core – The sphere of very hot metal at the
center of the Earth.
Mantle – The thick layer around the Earth’s
core
Crust – The thin, rocky layer of Earth’s surface
Magma – soft, nearly molten rock
Plate – a huge block of Earth’s crust
Weathering – A process that breaks rocks down
into small pieces
Erosion – The removal of small pieces of rock
by water, ice or wind
What is Mantle and Core pg 25
Earth
made of? It all works together!
Crust = land areas and ocean
floors
Heated mantle and core help
shape the crust
Crust floats on top of the
mantle
What
part of
the Earth
is Water
and Air?
More than 70% of Earth’s
surface is water. Oceans hold
97% of Earth’s water.
Fresh water is frozen in ice
sheets near N and S Poles.
How much
of Earth is air?
Atmosphere = layers of gas a few
miles thick.
Provides oxygen to
_________________
and carbon dioxide to ____________.
Mountains rise more than 2,000 ft above
sea level or surrounding land
Ex. Volcano
Hills have rounded tops, but are
lower and less steep than mountains
Plateau is large and mostly flat . It rises
above the surrounding land
One steep slope
Plains are large areas of flat land, but can
also be gently rolling
How are
volcanoes
a force
within
the Earth?
Heat inside the Earth constantly
reshapes the surface
Causes the rock to rise to
the surface
Volcanoes are formed when
magma pushes up the crust
Volcanoes spew lava or
molten rock. Magma can
push the Earth apart
along seams
What are
plates?
Huge blocks of Earth’s crust
These are continents or parts
of continents. Each plate is
part ocean floor.
Magma rises and cools
creating new crust and
pushing old crust away
from the seams.
Magma and plates pg 25
How are
volcanoes
and
Earthquakes
created?
Colliding ocean and land crust
sink and melt.
Volcanoes are mostly around
plates, but not always
Example: Hawaii
Earthquakes happen when two p
plates rub along faults
Faults are cracks in the Earth’s
crust. Faults happen when two plates
push together, the crust cracks and
splinters from pressure
How did
the world
become
the world?
Plates moved over hundreds
of millions of years
Pangea – 250 million yrs
150 million yrs
75 million yrs
Present continents
What are
the forces
on Earth’s
surface?
Weathering – process that
breaks rock down into tiny
pieces.
Weathering helps create
soil
Rock + decayed animal + plant material = soil.
What
causes
erosion?
Erosion is the removal of small
pieces of rock by water, ice, or
wind.
Ex: Appalachian
Mountains
Deposited material from
erosion creates new landforms
Ex: Plains