Transcript Inside the earth - Northside Middle School

Chapter 4 – Lesson 1
INSIDE THE EARTH
LESSON OBJECTIVES:
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Identify the layers of the Earth
by their chemical composition.
Identify the layers of the Earth
by their physical properties.
Describe a tectonic plate.
Explain how scientists know
about the structure of Earth’s
interior.
ICE AGE
EARTH MODELS
✕ Examine
the
avocado. Make
comparisons
about Planet
Earth.
THE COMPOSITION OF THE EARTH
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The Earth is divided into 4 layers—
the crust, the mantle, and the core (2)
based on the compounds that make up each
layer.
The Crust is the outermost layer of the
Earth. The crust is 5 to 100 km thick, and is
the thinnest layer of the Earth.
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There are two types of crust—continental
and oceanic. Oceanic crust is thinner and
denser than continental crust.
Temps range from -90 o C to 100 o C
*CONTINENT
✕Great
landmasses
surrounded by oceans
✕Made
of layers of rock:
✕Minerals...
THE COMPOSITION OF THE EARTH
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The Mantle is the layer of the Earth
between the crust and the core.
• Rock!!! Silicon, Oxygen, Magnesium, little
iron
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The mantle is much thicker than the crust
and contains 2/3’s of the Earth’s mass.
The crust is too thick to drill through
THE COMPOSITION OF THE EARTH
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The Core is the central part of the Earth
makes up about one-third of Earth’s mass
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Below the mantle. It has 2 areas:
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The Outer core ( Liquid ~ 2 200 o C)
2 250 km depth
Mostly of iron and smaller amounts of nickel
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THE COMPOSITION OF THE EARTH
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The Inner Core
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Solid ~ 2 000 - 5 000o C
1 200 km depth
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Mostly of iron and smaller amounts of nickel
THE COMPOSITION OF THE EARTH
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The Outer Core
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solid, spins inside the Liquid Outer Core
• Creates Magnetic Field around the Earth
THE PHYSICAL STRUCTURE OF THE EARTH
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The Earth is divided into five physical
layers:
The lithosphere
The asthenosphere
The mesosphere
The outer core
The inner core
5 Physical Layers 1) Lithosphere
“Litho”---- “Rock”
● uppermost rigid layer,
made of the crust &
the rigid part of upper
mantle
● divided into pieces --“Tectonic Plates”
5 Physical Layers 2) Asthenosphere
“Astheno”---- “Weak”
● soft layer of upper
mantle
● hot, soft rock, “plastic”
● Constant motion
● moves tectonic plates
5 Physical Layers 3) Mesosphere
“Meso”---- “Middle”
● Strong, lower part of
Mantle
● Dense rock, compact
● From Asthenosphere
to Outer Core
● Constant motion by ???
Crusts: Are not all alike!
Earth’s Mass
Continental (5-100 km)
Thicker, granite rock
lots of Silicon, Aluminum, Oxygen
Oceanic (5-30 km)
Thinner, denser,
basalt rock
more Calcium,
Magnesium, Iron
1% of
5 Physical Layers
4) Outer Core
5) Inner Core
Atmosphere
Layers of Atmosphere
TECTONIC PLATES
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Pieces of the lithosphere that move around
on top of the asthenosphere.
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rigid, outermost part of the mantle.
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“float” on the asthenosphere.
cover the surface of the asthenosphere
touch one another and move around.
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MAPPING THE EARTH’S INTERIOR
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deepest parts of the planet by measuring the
speeds of the seismic waves that travel
through the Earth’s interior during
earthquakes.
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By using seismographs, scientists have
learned that the Earth is made of different
layers.
WHAT IS THE SCIENCE OF GEOLOGY?
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Geology – the study of Earth
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Seismic Waves – Video
when earthquakes occur geologist record the
speed and paths of seismic waves to determine the
layers of the Earth
CONVECTION CURRENTS IN THE MANTLE
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HOT PARTICLES RISE
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COOL PARTICLES SINK
EXPAND>MORE VOL
LESS DENSE
DENSE (COLLECTED)
COOL PARTICLES SINK W/ GRAVITY
DEVELOPS UP & DOWN CURRENTS
(CONVECTION)
Dr Damon Teagle of the National Oceanography Centre in
Southampton, England and Dr Benoit Ildefonse from
Montpellier University in France, have announced jointly in an
article in Nature that they intend to drill a hole through the
Earth’s crust and into the mantle; 2018
Scientists
plan to drill all
the way down
to the Earth's
mantle!
Bob Yirka
NOTES:
WHAT WOULD BE FOUND ON A JOURNEY TO THE
CENTER OF THE EARTH?
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Draw the Earth’s interior.
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Label each section
Label the depth of each section
Label the temperature of each
section
Include a summary of each
layer.
DRAW & LABEL!!! COLOR TOO!!!
5
1
4
2
3
Can you explain the
Lithosphere vs. Asthenosphere?
PRESSURE (atmospheres)
4
Sea
level =
1 atm
3
230,000 – 1.3 million atm
As the depths increase:
What happens to pressure? What happens to Temp?
Read the following section summary.
The Earth is made up of three layers—the crust, the mantle, and
the core—based on chemical composition. Less dense compounds
make up the crust and mantle. Denser compounds make up the core.
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The Earth is made up of five main physical layers: the
lithosphere, the asthenosphere, the mesosphere, the outer core, and the
inner core.
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Tectonic plates are large pieces of the lithosphere that move
around on the Earth’s surface.
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The crust in some tectonic plates is mainly continental. Other
plates have only oceanic crust. Still other plates include both
continental and oceanic crust.
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Thick tectonic plates, such as those in which the crust is mainly
continental, displace more asthenosphere than do thin plates, such as
those in which the crust is mainly oceanic.
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Knowledge about the layers of the Earth comes from the study of
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EARTH ON THE MOVE!
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Constructive Forces – shape the surface by
BUILDING UP the mountains and
landmasses.
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Destructive Forces – slowly WEAR AWAY
mountains and, eventually every other
feature on the surface
EARTH ON THE MOVE!
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Examples of Constructive Forces:
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Examples of Destructive Forces:
WHAT DOES THIS IMAGE REPRESENT?
What type of Forces are at work here? Name 2
ENRICHMENT
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The inner core of the Earth is
simultaneously melting and freezing due
to…???