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Geologists: Scientists
that study the forces that
make and shape planet
Earth. They study the
chemical and physical
characteristics of rock.
Geologists study the
processes that create
Earth’s features and
search for clues about
Earth’s history.
Geology is the study of
the solid Earth and the
processes by which it is
shaped and changed.
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Paleontologists: These
scientists study the forms of
life existing in former
geologic periods.
The science of
Paleontology helps us learn
about the history of
different species that have
inhabited Earth.
Information we have
regarding dinosaurs, wooly
mammoths, trilobites, and
other extinct species come
from fossil formations
found and studied by
paleontologists.
Constructive Forces:
Shape the surface by
building up mountains
and landmasses.
(Example Surtsey-2
Miles)
 Destructive Forces:
Slowly wear away
mountains and
eventually every other
feature on the surface.
(Example:
Weathering)
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 Any
ideas???? (Hint it
is not because we
sent Brendan Frasier
down there)
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We know about the
composition of the interior of
the Earth because of Seismic
Waves. (Earthquake Waves)
The speed of these seismic
waves and the paths they take
reveal how the planet is put
together.
P (primary) waves can travel
through every layer of the
earth. In solids, these waves
generally travel almost twice
as fast as S waves and can
travel through any type of
material.
S (secondary) waves can only
travel through solids.
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are 4 main
layers to the Earth.
 Crust, Mantle, Outer
Core, and Inner Core.
 As you go towards the
center of the Earth
the temperature and
pressure increases
greatly.
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The layer of rock that
forms the Earth’s surface.
The crust includes rocks,
mountains, soil and
water.
The crust is the smallest
layer of the earth. (Apple
Example)
There are two types of
crust oceanic crust
(Basalt which is an
igneous rock) and
continental crust (rocks
like Granite which is an
igneous rock)
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The oceanic crust is 5km (3mi) to 10 km (6mi) thick and
is composed primarily of basalt, diabase, and gabbro.
The average density of the oceanic crust is 3g/cm³.
The continental crust is typically from 30 km (20mi) to
50 km(30mi) thick and is composed of sighlty less
dense rocks than those of the oceanic crust.
he average density of the continental crust is 2.7g/cm³.
Earth’s crust occupies less than 1% of the Earth’s
volume.
The temperature of the crust increases with depth,
reaching values typically in the range from about
200°C (392°F) to 400°C (752°F) at the boundary with
the underlying mantle.
The mantle is a layer of
hot soild material
 The mantle is solid but
has liquid like
characteristics. (It’s
kind of like Silly Putty)
 The mantle is the
largest of the layers of
the earth
 It is mainly composed
of silicon, oxygen, iron,
and magnesium.
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It begins about 6 miles(10 km) below the oceanic crust
and about 19 miles (30 km) below the continental crust
(see The Crust).
It is about 1,800 miles(2,900 km) thick and makes up
nearly 80 percent of the Earth's total volume.
The function of the mantle is to separate the inner
mantle and the outer mantle.
The average temperature is 5400 ºF (3000ºC),
nevertheless the rock is solid because of the high
pressures.
The bottom layer is tough liquid rock and probably
consists of silicates of iron and magnesium. The
temperature in this part is between 2520 ºF (1400ºC)
and 5400 º F (3000ºC) and the density is between
3.4g/cm³ and 4.3g/cm³. The upper layer of the outer
mantle consists of the same material but is stiffer
because of its lower temperature.
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The outer core is a layer of molten
metal that surrounds the inner core.
In spite of enormous pressure the
outer core behaves like a thick liquid.
Currents in the liquid outer core force
the solid inner core to spin at a
slightly faster rate than the rest of the
planet. These currents in the outer
core create the Earth’s magnetic field.
This is why you can use a compass
and the Earth is protected from some
of the harmful rays of the sun.
Composed of mostly Iron and Nickel
Its outer boundary lies 2,890 km
(1,800 mi) beneath the Earth's surface.
The temperature of the outer core
ranges from 4400 °C in the outer
regions to 6100 °C near the inner core
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The inner core is a dense
ball of solid metal.
It is also mainly
composed of iron and
nickel.
Temperature range is
probably between 2,0005,000 degrees Celsius
and about 1,216 km (760
mi) in radius.
The center of the inner
core is thought to be as
hot as the surface of the
sun.
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Plate Tectonics is the
geological theory that
states that pieces of
Earth’s crust are in
constant, slow motion,
drive by convection
currents in the Earth’s
mantle.
No plate can budge
without affecting the
other plates surrounding
it.
As the plates move, they
collide, pull apart, or
grind past each other.
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Plate movements cause
volcanoes to erupt, mountain
ranges to be formed, and
earthquakes to occur.
Plate Tectonics are
responsible for the
deformation of Pangea.
Plate Tectonics Introduction
Plate Tectonics Evidence
Movement of Earth's Tectonic
Plates
The Man Behind Plate
Tectonics
We will be reading more
about Plate Tectonics in a few
days.