Download Tectonic plates

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Bellringer #15
 Read
“Bats and Bridges” page 61
 Answer
the two What do you
think? Questions in your journal.
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Mysterious Fungus Ravages
North American Bat Populations
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Turbines Threaten Endangered Bats
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Homework
 Define
all of the vocab for
Chapter 3.
A
list of the words can be found
on page 86
 Vocab
is Due tomorrow!
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Bellrigner # 16
 What
is the Geosphere?
 Where
is most of the Geosphere
located?
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Chapter 3 The Dynamic Earth
Objectives
Describe the composition and structure of
the Earth.
 Describe the Earth’s tectonic plates.
 Explain the main cause of earthquakes
and their effects.
 Identify the relationship between volcanic
eruptions and climate change.
 Describe how wind and water alter the
Earth’s surface.

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The Earth as a System
The Earth consists of rock, air, water and living
things that all interact with each other.
Scientists divided this system into four parts:
1. The Geosphere (rock)
2. The Atmosphere (air)
3. The Hydrosphere (water)
4. The Biosphere (living things)
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The Earth as a Integrated System
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The Earth as a System
geosphere is the mostly solid, rocky part of
the Earth that extends from the center of
the core to the surface of the crust
atmosphere is the mixture of gases that
makes up the air we breathe.
* Nearly all of these gases are found in the
first 30 km above the Earth’s surface.
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The Earth as a System
hydrosphere makes up all of the water on or
near the Earth’s surface.
a. Much of this water is in the oceans, which
cover nearly three-quarters of the globe.
b. water is also found in the atmosphere, on
land, and in the soil.
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The Earth as a System
biosphere is the part of the Earth where life
exists.
a. extends from about 9 km above the
Earth’s surface down to the bottom of the
ocean.
b. The biosphere is therefore made up of
parts of the geosphere, the atmosphere,
and the hydrosphere.
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Discovering Earth’s Interior

Studying the Earth’s interior is not easy.

The deepest well that has been drilled into
Earth’s interior is only about 12 km deep.

An alternative method must be used to
study the interior of the Earth.
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Earth’s Interior

Scientists use seismic waves to learn
about Earth’s interior.

Seismic waves are the same waves that
travel through Earth’s interior during an
earthquake.

A seismic wave is altered by the nature of
the material through which it travels.
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Earth’s Interior

Seismologists measure changes in the
speed and direction of seismic waves that
penetrate the interior of the planet.

With this technique seismologists have
learned that the Earth is made up of
different layers and have inferred what
substances make up each layer.
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Earth’s Interior
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
Scientists divide the Earth into different
layers based on :
Composition-
what it is made of
Physical
Properties- any aspect
of an object or substance that can
be measured or perceived without
changing its identity
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Composition of the Earth
Earth is divided the into three major layers:
1. crust
2. mantle
3. core
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crust -the thin and solid outermost layer
of the Earth above the mantle.

makes up less than 1 percent of the
planet’s mass.

Is composed almost entirely of light
elements.

The crust is the Earh’s thinest layer.
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Composition of the Earth
Mantle layer of rock between the Earth’s
crust and core.
The mantle makes up 64 percent of the
mass of the Earth.
• Made of rocks of medium density.
Core the central part of the Earth below
the mantle, and is composed of the
densest elements.
• Innermost layer
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The Structure of the Earth

The Earth can be divided into five layers:
Lithosphere
2. Asthenosphere
3. Mesosphere
4. Outer Core
5. Inner Core
1.
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Layers of the Earth
1. lithosphere the solid, outer layer of the
Earth that consists of the crust and the
rigid upper part of the mantle.
•
It is a cool, rigid layer that is divided
into huge pieces called tectonic plates.
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Layers of the Earth
2. asthenosphere the solid, plastic layer of
the mantle beneath the lithosphere.
a. It is made of mantle rock that flows
slowly, which allows tectonic plates to
move on top of it.
3. Mesosphere
- Beneath the asthenosphere is the
lower part of the mantle.
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Layers of the Earth
4. Outer core is a dense liquid layer.
5. Inner core a dense, solid inner core,
made up mostly of iron and
nickel.
• Although the temperature of the inner core
is estimated to be between 4,000°C to
5,000°C, it is solid because it is under
enormous pressure.
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Five layers of Earth
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Opening Activity
 Work
with the people at your table
 Try
to fit all of the cut out pieces
together to form one large
landmass.
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Plate Tectonics
Tectonic plates
- are blocks of lithosphere that consist of the
crust and the rigid, outermost part of the
mantle and glide across the underlying
asthenosphere.
a. The continents are located on tectonic
plates and move around with them.
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The major tectonic plates include:
Figure 4 pg. 66
1. The Pacific plate
2. North America plate
3. South America plate
4. Africa plate
5. Eurasian plate
6. Antarctic plates
7. Nazca Plate
8. Indian plate
9. Australian plate
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Tectonic Plates
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Alfred Wegener a German
meteorologist developed the
theory of continenetal drift.
Relying on evidence from
various scientific fields,
Wegener proposed that all the
continents were once joined
into one landmass, which he
named Pangea.
Like many scientific theories,
contintental drift was scored
as its inception. Wegener’s
ideas were not given full
credence until decades later
when oceanographic research
found evidence for the
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process of seafloor spreading.
Plate Tectonics

Tectonic plates may:
Separate
(divergent boundaries)
Collide (convergent boundaries)
Slip past
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Seafloor Spreading
Process in which new seafloor forms as
molten rock from Earth's interior rises
toward the surface, pushing the existing
seafloor out of its way
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Subduction
Tectonic process that
involves one plate being
forced down into the
mantle at an oceanic
trench, where it
eventually undergoes
partial melting.
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Transform Boundaries
Horizontal plate
movement in
which one plate
slides past another
This movement
creates faults
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Plate Tectonics
•
Enormous forces are generated with
these actions causing mountains to
form, earthquakes to shake the crust,
and volcanoes to erupt along the plate
boundaries.
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Plate Tectonics
•
•
Where plates collide, the crust becomes
thicker and eventually forms mountain
ranges, such as the Himalaya Mountains.
Look at Figure 5 pg.67
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Earthquakes
•
A fault is a break in the Earth’s crust
along which blocks of the crust slide
relative to one another.
•
When rocks that are under stress
suddenly break along a fault, a series of
ground vibrations, known as earthquakes,
is set off.
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Earthquakes

Earthquakes are occurring all of the time,
but many are so small that we can not
feel them.

Other earthquakes are enormous
movements of the Earth’s crust and cause
widespread damage.
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Earthquake Devastation in Kashmir
Flattened by the massive earthquake that struck South Asia on Saturday,
October 8, 2005, portions of the village of Balakot slide down a hillside and
block the main road below.
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Earthquakes

The Richter scale is used to quantify the
amount of energy released by an
earthquake.

The measure of the energy released by an
earthquake is called magnitude.

The smallest magnitude that can be felt is
2.0, and the largest magnitude ever
recorded is 9.5. Magnitudes greater than
7.0 cause widespread damage.
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Earthquakes

The majority of earthquakes take place at
or near tectonic plate boundaries because
of the enormous stresses that are
generated when tectonic plates separate,
collide or slip past each other.
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Where do Earthquakes Occur?
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The 1964 Good Friday Earthquake
On March 27, 1964 the world’s second largest earthquake ever instrumentally
recorded shook Southcentral Alaska for up to 5 minutes, an eternity for someone
on the ground. At 9.2 on the Richter scale it released a million times more energy
than a 5.2 earthquake, which occurs several times a year in this region.
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Bellringer # 17
 How
can volcanoes be harmful to our
environment?
 How
can volcanoes be helpful to our
environment?
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Volcanoes
volcano is a mountain built from magma, or
melted rock, that rises from the Earth’s
interior to the surface, and can occur on
land or in the sea.
•
Volcanoes are often located near tectonic
plate boundaries where plates are either
colliding or separating from one another.
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Volcanoes

Volcanoes may occur on land or under the
sea, where they may break the ocean
surface as islands.

Figure 7 shoes, the majority of the wolrd’s
active volcanoes on land are located along
tectonic plate boundaries that surround the
Pacific Ocean.
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Volcanoes: The Ring of Fire
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Global Effects of Volcanic
Eruptions
Major volcanic eruptions can change Earth’s
climate for several years. Fig 8 pg 69
 In large eruptions, clouds of volcanic ash and
sulfur rich gases may reach the upper
atmosphere, and spread across the planet
reducing the amount of sunlight that reaches
the Earth’s surface.
 The reduction in sunlight can cause a drop in
the average global surface temperature.

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Effects of Erosion
The Earth’s surface is continually battered
by wind and scoured by running water,
which moves rocks around and changes
their appearance.
Erosion the process in which the materials
of the Earth’s surface are loosened,
dissolved, or worn away and transported
form one place to another by a natural
agent, such as wind, water, ice or gravity.
Ex. Wind erosion and Water erosion
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Homework
 Complete
the Section 1
Review questions # 1, 2, 3 and
4 on page 70
 Due
Tomorrow.
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Bellringer # 18

Name the 3 compositional layers of the
Earth and the 5 physical layers of the
Earth.
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Bellringer #20

Why do planes fly so high, often 10km off
the ground?
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Objectives Section Two Atmosphere
Describe the composition of the Earth’s
atmosphere.
 Describe the layers of the Earth’s
atmosphere.
 Explain the greenhouse effect.

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The Atmosphere
Atmosphere a mixture of gases that surrounds a
planet, such as Earth.
a. Nitrogen, oxygen, carbon dioxide, and
other gases are all parts of this mixture.
b. Gases can be added to and removed
from. (which constantly happens)
c. The atmosphere also insulates Earth’s surface.
d. This slows the rate at which the Earth’s surface
loses heat and keeps Earth temperature at
which living things can survive.
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Composition of the Atmosphere

In addition to nitrogen and oxygen, other
gases such as argon, carbon dioxide,
methane, and water vapor make up the
rest of the atmosphere.
Nitrogen makes up
78 percent of the
Earth’s
atmosphere, and
enters the
atmosphere when
volcanoes erupt
and when dead
plants and animals
decay.
Oxygen is the
second most
abundant gas
in the
atmosphere
and is primarily
produced by
plants.
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Layers of the Atmosphere
The atmosphere is divided into four layers
based on temperature changes that occur
at different distances above the Earth’s
surface.
•
•
•
•
The Troposphere
The Stratosphere
The Mesosphere
The Thermosphere
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Layers of the Atmosphere
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The Troposphere
- the lowest layer of the atmosphere in
which temperature drops at a constant
rate as altitude increases.
a.
part of the atmosphere where weather
conditions exist.
b. extends to 18 km above Earth’s surface.
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The Stratosphere
- lies immediately above the troposphere
and extends from about 10 to 50 km
above the Earth’s surface.
a. Temperature rises as altitude increases
because ozone in the stratosphere
absorbs the sun’s ultraviolet (UV)
energy and warms the air.
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The Stratosphere
Ozone is a gas molecule that is made up of
three oxygen atoms.
a. Almost all of the ozone in the
atmosphere is concentrated in the
stratosphere.
b. Because ozone absorbs UV radiation, it
reduces the amount of UV radiation that
reaches the Earth. UV radiation that
does reach Earth can damage living
cells.
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The Mesosphere
- layer above the stratosphere is the
mesosphere.
a. extends to an altitude of about 80 km.
b. the coldest layer of the atmosphere
where temperatures have been measured
as low as –93ºC.
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The Thermosphere
- located farthest from Earth’s surface is
the thermosphere.
a. Here, nitrogen and oxygen absorb solar
radiation resulting in temperatures
measuring above 2,000 ºC.
b. The air in the thermosphere is so thin
that air particles rarely collide, so little
heat is transferred, and would therefore
not feel hot to us.
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The Thermosphere
The absorption of X rays and gamma rays
by nitrogen and oxygen causes atoms to
become electrically charged.
 Electrically charged atoms are called ions,
and the lower thermosphere is called the
ionosphere.
 Ions can radiate energy as light, and these
lights often glow in spectacular colors in
the night skies near the Earth’s North and
South Poles called the Northern Lights.

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Northern Lights
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The Greenhouse Effect
greenhouse effect
- the warming of the surface and lower
atmosphere of Earth that occurs when
carbon dioxide, water vapor, and other
gases in the air absorb and reradiate
infrared radiation.
a.
Without the greenhouse effect, the Earth
would be too cold for life to exist.
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The Greenhouse Effect
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The Greenhouse Effect

The gases in the atmosphere that trap and
radiate heat are called greenhouse gases.

The most abundant greenhouse gases are
water vapor, carbon dioxide, methane, and
nitrous oxide, although none exist in high
concentrations.

The quantities of carbon dioxide and
methane in the atmosphere vary
considerably as a result of natural and
industrial processes.
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Bellringer #21
 Read
“Hydrothermal Vents” on
page 78
 Answer
the questions on page 79
in your journal.
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Objectives Section Three –
Hydrosphere & Biosphere

Name the three major processes in the
water cycle.

Discuss the factors that confine life to the
biosphere.

Explain open and closed systems.
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Hydrosphere - includes all of the water on or
near the Earth’s surface.
Examples:
oceans, lakes, rivers, wetlands, polar ice
caps, soil, rock layers beneath Earth’s
surface, and clouds.
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Water cycle - is the continuous movement
of water from the ocean to the atmosphere
to the land and back to the ocean.
Evaporation - is the change of a substance
from a liquid to a gas.

Water continually evaporates from the
Earth’s oceans, lakes, streams, and soil,
but the majority evaporates from the
oceans.
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Condensation - is the change of state
from a gas to a liquid.

Water vapor forms water droplets on dust
particles which then form clouds in which
the droplets collide to create larger,
heavier drops that then fall from the clouds
as rain.
Precipitation - any form of water that falls
to the Earth’s surface from the clouds, and
includes rain, snow, sleet, and hail.
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Water cycle
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The Biosphere
Biosphere - the part of Earth where life
exists, extending about 11 km into the
ocean and about 9 km into the
atmosphere.

The materials that organisms require must
be continually recycled.

Gravity allows a planet to maintain an
atmosphere and to cycle materials
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The Biosphere

The biosphere is located near Earth’s
surface because most of the sunlight is
available near the surface.

Plants need sunlight to produce their food,
and almost every other organism gets its
food from plants and algae.

Most of the algae float at the surface of the
ocean and is known as phytoplankton.
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Energy Flow in the Biosphere
Closed systems are systems that cannot
exchange matter or energy with its
surroundings.
 Open systems are systems that can
exchange both matter and energy with its
surroundings.
 Earth is essentially a closed system with
respect to matter, but an open system for
energy as energy travels from plant to
animal which is eaten by other animals. In
the process, some energy is lost as heat to
the environment.

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Energy Flow in the Biosphere

The energy used by organisms must be
obtained in the biosphere and must be
constantly supplied for life to continue.

When an organism dies, its body is broken
down and the nutrients in it become
available for use by other organisms.

This flow of energy allows life on Earth to
continue to exist.
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Global Navigation

Imagine you are planning a voyage around the
world. You can choose any route you wish, but
you must sail with the currents.

Map out your route showing
the names of the currents
 Where you are going to start
 Where you are going to end

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Bellringer #22

How can gases be added and taken away
from our atmosphere?

List three examples.
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