Download Theory of Plate Tectonics

Welcome to Geology
Geology Vocabulary
1. Geology
2. Crust
3. Mantle
4. Core (outer/inner)
5. Continental crust
6. Oceanic crust
7. Tectonic plates
8. Lithosphere
9. Asthenosphere
10. Convection currents
11. Pangaea
12. Continental Drift
13. Earthquake
14. Tsunami
15. Volcano
16. Continental Boundaries
17. Rift
18. Faults
19. Weathering
20. Fossils
21. Paleontologist
22. Evolution
23. Trilobites
Geology
What is geology?
The science that deals with the earth's:
• physical structure and substance
• its history
• and the processes that act on it.
• What is a geologist?
• Why is it important to study our planet Earth?
Layers of the Earth
• How many layers are there?
• Can you stand on all of the layers?
• What layer are we standing on right now?
A Crust
Mantle
B
C Outer
D Core
Inner
Core
Name the Earth’s Layers
Layers of the earth
Layers of the Earth
• What Is the temperature of the layers?
A. Crust?
• 200-400 degrees celsius (392 – 752 deg. F)
B. Mantle?
• 300 deg. celsius (572 – 932 deg. F) to 4500
degrees celsius (8,132 deg.F)
C. Core?
• 4400 degrees celsius (7,952 deg. F) to 5505
degrees celsius (9941 deg F)
D. What are the layers made up of?
• iron and nickel
What is the Lithosphere?
• The crust and part of
the upper mantle =
• Lithosphere
• 100 km thick
• Less dense than the
material below it so it
“floats”
What is the Asthenoshere?
• The plastic layer below the lithosphere =
• asthenosphere
• The plates of the lithosphere float on the
asthenosphere
Pangaea
A supercontinent that existed during the late Paleozoic and early Mesozoic eras,
forming approximately 300 million years ago.
It began to break apart around 100 million years after it formed.
Pangaea - Theory of Continental Drift
• The theory that over time, the continents are
drifting.
• In 1912 Alfred Wegener hypothesized that at
one point in time all the continents were part of
one super continent called Pangaea
• Is there evidence to show proof of this?
• Yes, the evidence came from the shape of the
land, fossils, landforms, and the ancient ice age
How did it come from all of this?
• South America and Africa's shape would line up
perfectly
• Matching animal and plant fossils have been
found on different sides of the ocean
• Plus landforms like mountains and rock
formations match on different continents
• https://www.youtube.com/watch?feature=player
_embedded&v=pwB9F8Nl6zM&x-ytts=1421782837&x-yt-cl=84359240
Pangaea
http://www.bbc.co.uk/science/earth/earth_timeline/pangaea#p00fztwb
(1:20)
Pangaea
• What is pangea?
• Pangaea is the theory of continental drift
• At one point in time all the continents were part of one
super continent called Pangaea
• Is there evidence to show proof of this?
• Yes, the evidence came from the shape of the land,
fossils, landforms, and the ancient ice age.
• How did it come from all of this?
• South America and Africa's shape would line up perfectly
• Also, matching animal and plant fossils have been found
on different sides of the ocean
• Plus landforms like mountains and rock formations
match on different continents
• What is the Theory of Continental Drift:
• The theory that over time, the continents are drifting.
What is Plate Tectonics
• The Earth’s crust and upper
mantle are broken into sections
called plates
• Plates move around on top of the
mantle like rafts
Plate Tectonics
Plate Tectonics for Kids (5:10)
http://www.youtube.com/watch?v=tcPghqnnTVk
Plate Tectonics - A Documentary (7:39)
http://www.youtube.com/watch?v=1-HwPR_4mP4
Tectonic Plates
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Make the world move
They cause geological processes and hazards?
Earthquakes, volcanoes and
Mountain ranges too
But that's not all…….
there are three different boundaries and so
much to learn about them.
Major Tectonic Plates of the World
http://thebritishgeographer.weebly.com/plate-tectonic-theory.html
2 Types of Plates
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Ocean plates –
plates below the oceans
Continental plates –
plates below the continents
Tectonic Plates Boundaries
Tectonic Plate Boundaries (1:10)
https://www.youtube.com/watch?v=dXDYoCqwSbM
Convergent Boundary
• This is where the plates crash and crunch together
• Three types of convergent boundaries:
1. Continental to continental
2. Oceanic to oceanic
3. Continental to oceanic
• When the oceanic and continental collide, the
oceanic plate goes under the continental plate
• And creates a trench
• The rock breaks and creates an earthquake or
tsunami.
Convergent Boundary
• As the oceanic plate pushes into the continental plate
• The rocks get pushed into the hotter interior, and starts a
process called
• “subduction” - the rocks melt and rise and this creates
volcanic eruptions
• An example of this type of collision is on the plate of South
America where the oceanic Nazca Plate is crashing into the
continent of South America. The crash formed the Andes
Mountains
• the long string of volcanoes along the mountain crest, and the
deep trench off the coast in the Pacific Ocean.
• Continental to continental plates collide and makes mountains
Convergent Boundaries
• Boundaries between two plates
are doing what?
• colliding
 
• How many types?
• 3 types…
Type 1
• Ocean plate colliding with a less
dense
• continental plate
• Subduction Zone:
• where the less dense plate slides
• under the more dense plate
• What occur at subduction zones?
• VOLCANOES
Andes Mountains,
South America
Type 2
• Ocean plate colliding with
• another ocean plate
• The less dense plate slides
• under the more dense plate
• creating a subduction zone called
• a TRENCH
Aleutian Islands, Alaska
Type 3
• A continental plate colliding with
• another continental plate
• What type of zone takes place?
• Collision Zones
• What are formed at these places
where the plate is folded and
thrusted?
• Mountains
What happens to the crust when the
volcanoes form?
• The crust gets pushed under and melts and the
crust becomes magma or lava for the volcano,
when the volcano is active
• https://www.youtube.com/watch?feature=player
_embedded&v=ep2_axAA9Mw&x-ytts=1421782837&x-yt-cl=84359240e
•
Divergent Boundary
• This is when the earths brittle surface layer (the lithosphere) is
being pulled apart
• It typically breaks along parallel faults that tilt slightly outward from
each other
• As the plates separate along the boundary, the block between the
faults cracks and drops down into the soft, plastic interior (the
asthenosphere)
• The sinking of the block forms a central valley called a rift
• Magma (liquid rock) seeps upward to fill the cracks
• New crust is then formed along the boundary
• Earthquakes occur along the faults, and volcanoes form where the
magma reaches the surface.
•
https://www.youtube.com/watch?x-yt-cl=84359240&x-ytts=1421782837&feature=player_embedded&v=t-ctk4KR-KU
Divergent Boundaries
• Boundary between two plates that
are moving
• apart or rifting

• RIFTING causes SEAFLOOR
SPREADING
Features of Divergent
Boundaries
• Mid-ocean ridges
• rift valleys
• fissure volcanoes
Transform boundaries
• This is where plates slide horizontally past each other moving in
opposite directions
• Creating a massive amounts of energy to be built up
• Sometimes causing large earthquakes to occur
• The most famous transform boundary in the world is the San
Andreas fault.
• The San Andreas fault zone is about 1,300 kilometers long and
slices through two thirds of California at an average rate of about 5
centimeters per year
• https://www.youtube.com/watch?x-yt-cl=84359240&x-ytts=1421782837&v=x1LELKFXVSk&feature=player_embedded
Transform Fault Boundaries
• Boundary between two plates that
are sliding past each other
• What geological process occurs at
this boundarary?
• EARTHQUAKES along faults
San Andreas Fault, CA
Could a rock that is sticking out stop
the plates from moving?
• No the plates would grind the rock down
• Could the world start to break up?
• Yes it could happen, but at such a slow rate we do not
need to worry about it.
Causes of Plate
Tectonics
Convection Currents
• Hot magma in the Earth moves
toward the surface
• Then cools, and sinks again.
• Creates convection currents
beneath the plates that cause the
plates to move.
Earth’s Natural Events
The surface of the Earth and our environment have been
shaped substantially
by the behavior of volcanoes, earthquakes, tsunamis, and the
plate tectonic forces that foster them.
The Major players in the dynamic system that fashions the
environment of the Earth’s surface.
Environmental Literacy Council National Science Teachers Association
http://enviroliteracy.org/nsfmod/NaturesFury.pdf
How volcanos formed:
https://www.youtube.com/watch?v=6Z4as_imJfM
Yellowstone Caldera : The Biggest Volcanic Eruption Ever Awaits Mankind
https://www.youtube.com/watch?v=-iGJlYgp43s
Earthquakes
• Secrets Of The Earth: Hoover Dam
Causes Quakes (1:25)
• https://www.youtube.com/watch?v=jM4KAJvt
2PI&x-yt-cl=84359240&x-ytts=1421782837&feature=player_detailpage
Haiti Earthquake –
January 12, 2010
Tsunami
Japan 2011 –
1. National Geographic - http://news.nationalgeographic.com/news/2011/03/pictures/110311tsunami-earthquake-japan-hawaii-science-world-waves/#/japan-tsunami-earthquake-hitsnortheast-airplanes_33137_600x450.jpg
2. http://www.youtube.com/watch?v=V2taJExhV6g
3. Thailand Dec. 2004 - http://www.youtube.com/watch?v=1J8Feyr38Ss
How Tsunamis Work
• https://www.youtube.com/watch?v=Wx9vPvT51I&x-yt-cl=84359240&x-ytts=1421782837&feature=player_detailpage
Facts about tsunamis
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A series of ocean waves that sends surges of water
Reaching heights of over 100 feet (30.5 meters), onto land.
Cause widespread destruction when they crash ashore.
Caused by large, undersea earthquakes at tectonic plate boundaries.
The ocean floor at a plate boundary rises or falls suddenly and it
displaces the water above it and launches the rolling waves that will
become a tsunami.
Most tsunamis (80% happen within the Pacific Ocean’s “Ring of Fire,”
A geologically active area where tectonic shifts make volcanoes and
earthquakes common.
Tsunamis may also be caused by underwater landslides or volcanic
eruptions.
Or by the impact of a large meteorite plunging into an ocean.
Facts Cont’d
• Tsunamis race across the sea at up to 500 miles (805 kilometers) an
hour—about as fast as a jet airplane
• At that pace they can cross the entire expanse of the Pacific Ocean in
less than a day.
• And their long wavelengths mean they lose very little energy along the
way.
• In deep ocean, tsunami waves may appear only a foot or so high.
• But as they approach shoreline and enter shallower water they slow
down and begin to grow in energy and height.
• The tops of the waves move faster than their bottoms do, which causes
them to rise precipitously.
• A tsunami’s trough, the low point beneath the wave’s crest, often
reaches shore first.
Facts Cont’d
• When it does, it produces a vacuum effect that sucks coastal water seaward
and exposes harbor and sea floors.
• This retreating of sea water is an important warning sign of a tsunami,
because the wave’s crest and its enormous volume of water typically hit
shore five minutes or so later.
• Recognizing this phenomenon can save lives.
• A tsunami is usually composed of a series of waves, called a wave train, so
its destructive force may be compounded as successive waves reach shore.
• People experiencing a tsunami should remember that the danger may follow
the first wave
• Some tsunamis do not appear on shore as massive breaking waves but
instead resemble a quickly surging tide that inundates coastal areas.
• The best defense against any tsunami is early warning that allows people to
seek higher ground.