Transcript Plate Tectonics

Liz LaRosa for use with my 5th Grade Science Class
http://www.middleschoolscience.com 2009
The Earth's rocky
outer crust solidified
billions of years ago,
soon after the Earth
formed.
This crust is not a
solid shell; it is broken
up into huge, thick
plates that drift atop
the soft, underlying
mantle.
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__________layer
5 –_____km thick
Made of Oxygen, Silicon, Aluminum
Layer of Earth
_______the
_______and the ____
• Contains ______of the
Earth’s _________
• Has more magnesium
and less aluminum
and silicon than the
crust
• Is _________than the
crust
•
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Asthenosphere: from greek word “______”.
 Zone of weak, easily deformed rock in the upper
mantle.
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Lithosphere: from greek word “_______”.
 ________on the asthenoshpere
 Includes all of the _______and part of the upper
_________.
 ________rigid portion of the Earth
 Divided into ________major plates…
_____the ______and
to the center of the
Earth
 Believed to be
________Iron,
smaller amounts of
Nickel, almost no
Oxygen, Silicon,
Aluminum, or
Magnesium
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Greek – “tektonikos” of a _________
_________scientists use to explain plate
movement
Pieces of the lithosphere that _____around
Each plate has a _______
Fit together like _________puzzles
Float on top of ______similar to ____cubes
in a bowl of water
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Plates in __________motion….very slow
 Moves only few cm per year
Boundaries where plates _______are usually the site
of _________and volcanoes
 ________of plates _______Earth’s _______to
________constantly and dramatically (crumpling
rocks, folding them, stretching and cracking)
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 Moves continents around globe
 Causes earthquakes and volcanic eruptions
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Transfer of _______
________take place _______a source of heat.
 Ex. Hot water is less dense than cold water and
rises, causing convection currents which transport
energy.
http://pubs.usgs.gov/gip/dynamic/unanswered.html
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Plates move ______from each other along
_______boundaries
Plates ______along a ________boundary
Plates _____past each other along _____fault
boundaries
 These plate movements have produced _____of
the world’s volcanoes, earthquakes, high
mountain ranges, and deep ocean trenches
Alfred Wegener 1900’s
Continents were once a
_______land mass that
________apart.
________of the same plants
and animals are found on
different continents
Called this supercontinent
_______, Greek for “all Earth”
______Million years ago
http://members.enchantedlearning.com/subjects/astronomy/planets/earth/Continents.shtml
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The continents and oceans are ____Earth’s
________.
Because plates ______, the continents we live
on today were ______places in the past.
They will ______to ______in other positions
in the future!
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Mid Ocean Ridges – underwater _______
chains that run through the Earth’s Basins
______ _____to the surface and _____and
_____crust forms
_____Crust is _____
farther away from the ridge
http://pubs.usgs.gov/gip/dynamic/understanding.html
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Caused by _____being pushed _____under a
plate
Magma presses against _____
_____and stretches lithosphere until it cracks
Magma _____into the gap and _____to form
new crust
http://pubs.usgs.gov/gip/dynamic/understanding.html
http://www.geology.com
http://www.geology.com
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_____kinds of collisions possible
 ______plate collide with ______plate: one of the
plates is pushed under the other.
▪ The plate that is forced down, melts…creating a trench
 _____ _______plates collide: one forced under
other.
▪ Plates crumple and fold, forming mountain ranges
 _____plate collides with _____plate: oceanic plate
forced downward.
▪ Mountains and volcanoes form along the boundary
between plates
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80% of the worlds volcanoes and 90% of all
earthquakes occur along convergent
boundaries!!!
http://pubs.usgs.gov/gip/dynamic/understanding.html & http://www.geology.com
http://pubs.usgs.gov/gip/dynamic/understanding.html & http://www.geology.com
http://pubs.usgs.gov/gip/dynamic/understanding.html & http://www.geology.com
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_____plates move past each other in
_____directions
www.geology.com
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95% of all earthquakes occur at or near the
edges of moving plates, along great cracks in
Earth’s crust called faults.
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As plates ______to move, rocks put under
great ______
 Rocks bend and stretch until they reach their
______point
 Suddenly, rocks ______and move into
______positions
 A jolt on energy is released
▪ Felt as ______
▪ (watch YOU TUBE video)
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A volcano is a ______that may form around
the ______as the lava cinders build up
Occurs at ______boundaries
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______, or molten rock beneath Earth’s
surface is ______up through an ______in
Earth’s surface.
 Molten rock _____as lava
 Hot molten _____is pushed ______to form
______mountains
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In the South Pacific the water is much
warmer than normal. Environmentalists
have said that Global Warming causes
it. Other Scientists have noted there is a
substantial amount of volcanic activity in
that same area. It has a tendency to warm
water, also. Here’s an interesting set of
photos.
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Name the 3 main layers of the Earth
What is a tectonic plate?
What was Pangea?
What is Sea-Floor spreading?
Name the three different types of plate
boundaries and one location on Earth for
each one
What are earthquakes and how do they
happen?
What are volcanoes and how do they form?