Geosphere
• Solid part of the
Earth’s crust
that consists of
all rock, and the
soils and
sediments on
Earth’s surface.
• Most located in
Earth’s interior
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Earth’s Interior
• Seismic Waves: the
waves that travel
through the Earth’s
interior during an
earthquake.
• Altered by the type of
material that it travels
through.
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Seismologists
• Scientists who
measure changes in
these waves to
determine that the
earth’s interior is
made in layers.
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Composition of the Earth
• Three layers:
• crust
• mantle
• core
• Density increases
towards the center of
the Earth
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Crust
• Thin, outer layer.
• Made up of light
elements
• less than 1% of
Earth’s mass
• 5-70km thick
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Mantle
• Layer beneath the
crust
• 84% of mass of Earth
• 2,900 km thick
• Made of
• Lithosphere (20%)
• Asthenosphere (9%)
• Mesosphere (55%)
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Lithosphere
• Outer layer
• cool, rigid
• divided up into
huge tectonic
plates
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Asthenosphere
• 250 km thick
• solid, plastic
layer made of
rock
• flows very slowly
and allows
tectonic plates to
move across
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Mesosphere
• 2,250 km thick
• “middle” sphere
• lower part of mantle
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Core
• 3,248 km radius
• sphere of hot, dense
nickel and iron
• 4,000 - 5,000 °C
• 15% of the Earth
• Made of
• Outer Core (7.5%)
• Inner Core (7.5%)
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• Outer Core; 2,200 km
thick, outer shell,
made of liquid nickel
and iron
• Inner Core: 1,228 km
radius; a sphere of
solid iron and nickel
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• Be able to draw and label the three layers of the earth
(crust, mantle, and core) as well as the 5 layers based
on physical properties (lithosphere, asthenosphere,
mesosphere, outer and inner core).
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What is the rock cycle?
• To show how rocks slowly change through time,
scientists have created a model called the rock
cycle.
• It illustrates the processes that create and change
rocks.
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Rock Cycle Continued
• The rock cycle shows the three types of rock— igneous,
metamorphic, and sedimentary—and the processes that form them.
• Weathering and Erosion – Weathering is the natural break down of
rocks into smaller and smaller pieces. Erosion is the movement of
broken rock from higher to lower elevations (down mountains and
along streams).
• Melting – Solid rock changing into magma due to very high heat
• Heat and Pressure – Under many layers of earth’s crust, rock is
exposed to a lot of heat and pressure
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The
Rock Cycle explains
how Rocks and Natural Processes
are related
weathering
Sedimentary Metamorphic
Igneous
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The Geosphere and Us
• Volcanoes, earthquakes,
and landslides
• Provides soil, energy,
and minerals
• Mining and pollution
affect geosphere