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Plate Tectonics
Notes and Activities
Name ___________________
Assignment for Vocabulary

On a separate sheet of paper, list the words below 1 to 16 and define them using your textbook, a
dictionary, the Internet, or any other source you choose. Just get it done!!!
Once you have defined the words read over each word so that you are able to understand its meaning.
I will collect and grade your completed list or give a matching QUIZ prior to the test on this
information as a homework assignment.
Number each word 1 through 16:
Asthenosphere
Divergent
Convergent
Transform Boundary
Mid-Ocean Ridge
Rift
Continental Crust
Hot Spot
Compression
Plate Tectonics
Subduction
Faults
Extension
Shear
Oceanic Crust
Convection Current
Plate Tectonics Notes
Earth's Internal Structure
Layers of the Earth
1. Inner Core
_______________ phase
made of _______________ and _______________
_______________ºC
_______________ km from the surface
_______________ km thick
2. Outer Core
_______________ phase
made of _______________ and _______________
_______________ºC
_______________ km from the surface
_______________ km thick
3. Mantle - "The Mush Zone"
_______________ phase
made of _______________ and _______________
_______________ºC
_______________ km from the surface
_______________ km thick
4. Crust
_______________ layer - where we live
Thickness depends on where you are
Ocean Crust
_______________ thick at deepest points in the ocean
Young rocks - 200 million years old
Continental Crust
_______________ thick
Rocks up to 3.8 billion years old
*No drill has ever gotten deeper than 9 miles into the earth’s crust
Original Theory of Continental Drift
Alfred Wegener
1912 - Said the shapes of the continents were no coincidence
They were like Puzzle Pieces
Theory of Continental Drift
The continents were once _______________ and named _______________ which means "all
land".
About _______________ years ago they broke apart and moved to their current positions.
Wegener could not explain how or why this occurred. He thought the continents floated around the
Earth’s surface. His theory was rejected based on lack of evidence. This led to the commonly
accepted theory today, _______________.
Evidence for Plate Tectonics
Pangaea
225 million years ago, all of the continents fit together as one large continent called Pangaea. Since
then, the continents, on their plates, have been moving apart. They continue to move apart today.
The theory of plate tectonics has taken Continental drift and explained a couple of things that
Wegener could not:
The Continents are on large _______________. They move in an _______________ and
_______________ way. The large _______________ float on the _______________ and move as
_______________ in the _______________ make it flow.
Convection currents are similar to ocean currents.
Hot magma rises and cool magma sinks. It moves like a conveyer belt
Five pieces of Evidence demonstrate that the continents move in an organized, predictable fashion.
1. _______________ of the Continents, especially the continental shelves.
A. _______________ by waves
B . _______________ were not included in your pictures
C. Glacial melt increased _______________
2. _______________ of the same organisms can be found on continents that are separated by
thousands of miles today.
A. These animals could not swim
B. The climate of places, like Antarctica, today couldn’t support this life
3. Glacial Evidence: A Glacier is a mass of ice that moves slowly over land. It is so heavy, it
leaves grooves in the ground. Similar grooves can be found on many continents due to the same
glacier
4. Rocks: Rocks in Appalachian Mts. are similar to rocks in Greenland and Western Europe.
Rocks on the east coast of South America are similar to rocks on the west coast of Africa.
5. Hot Spots and Volcanic Island Arcs (Hawaii)- As the plate moves, it carries the hot spot
island with it, creating an island arc.
Plate Boundaries
The movement of the plates is most evident along the boundaries of the plates. There are three types
of boundaries: _______________ where the plates are separating from one another,
_______________ where the plates are moving toward one another, and _______________ where
the plates are sliding past one another.
1. Divergent Plate Boundary
Two plates moving _______________ each other
Examples: _______________ and _______________ of Africa
In many cases the Sea Floor pulls apart in some places, allowing magma to come to the
surface through the cracks.
Evidence for Sea-floor Spreading
1. Age of Rocks: _______________ rocks are closest to ridge and
_______________ rocks are farthest from the ridge.
2. Magnetic Clues: Iron in magma hardens in alignment with earth’s magnetic
field (N. and S. Pole). The Earth’s magnetic poles have reversed many times.
2. Convergent Plate Boundary
Two plates _______________
3 types of convergent plate boundaries
A.Collision- 2 continental plates collide- Himalayan Mountains
B. Ocean-Continent Subduction- An oceanic and continental plate collide forming
trenches and volcanoes- Andes Mountains.
C. Ocean-Ocean Subduction: 2 oceanic plates colliding forming trenches and
volcanoes- Island of Japan
3. Transform Boundary
Two plates _______________ each other- San Andreas Fault
Volcanoes
Parts of a Volcano
3 main types of Volcanoes
1. Shield: Flowing lava, Mafic, dark color, higher density, flows easily, lava
2. Cinder cone: explosive eruption of cinders into atmosphere, Felsic, light color,
lower density, doesn't flow
3. Composite: combination of explosive eruption and lava flow.
Faults
There are three major types of faults, or breaks along which rock layers move.
1. Normal fault:
- Caused by tension on the rock layers, such as along a convergent boundary.
- Layers break and move apart.
2. Reverse fault:
- Caused by compression on the rock layers, such as along a divergent boundary.
- Layers break and move toward one another.
3. Strike-Slip fault
- Caused by side-to-side motion, such as along a transform boundary.
- Layers slip past one another.
Earthquakes
Assignment for Vocabulary
On a separate sheet of paper, list the words below 1 to 13 and define them using your textbook, a
dictionary, the Internet, or any other source you choose. Just get it done!!!
Once you have defined the words read over each word so that you are able to understand its meaning.
I will collect and grade your completed list or give a matching QUIZ prior to the test on this
information as a homework assignment.
Number each word 1 through 13:
Earthquake
Magnitude
Normal Fault
Reverse Fault
Seismograph
Seismogram
Tsunami
Epicenter
Transform Fault
Seismologist
Focus
Seismic Wave
Intensity
Earthquakes
An earthquake happens when two large rock slabs that are part of _______________ move past each
other. This signals a shift in the crust of the Earth as the plates move. There are two major points that refer
to earthquakes, the _______________ is the point under the Earth’s surface where the rocks actually slide
pat one another. The _______________ is the point on the surface directly above the focus.
Earthquake Waves
When an earthquake happens along a _______________, it sends waves out in all directions. There are
three major forms of waves the come from an earthquake. ___-waves travel along the surface and do a lot
of damage but don’t go very far. ___-waves and ___-waves travel into the Earth and can be recorded far
away from the _______________of the earthquake. P-waves are _______________ waves that shake
rock back and forth. They travel through solid or liquid and move _______________. S-waves, on the
other hand, are _______________ waves that move things up and won or side-to-side. They travel
through solid but not liquid and travel _______________than P-waves. Since the mantle and the Inner
Core are _______________parts of the interior of the Earth, both P- and S-waves could travel through
them. The Outer Core is _______________, so S-waves cannot travel through it. When you look into the
interior of the Earth, P- and S-waves can travel through the mantle but only P-waves can travel through
the Outer Core, and therefore, the Inner Core.
Shadow Zones
There are some areas of the Earth that do not receive waves from an earthquake. The P-waves slow down
when they hit the core. This causes the waves to bend, or _______________. As they _______________,
a shadow zone is left in the shape of a doughnut on the opposite side of the Earth from the focus, as seen
in the diagram below. No waves hit the shadow zone.
Finding an Earthquake Epicenter
The epicenter of an earthquake is the point on the surface of the Earth directly above the focus. You can
find the epicenter of an earthquake using the data from at least three seismographs. A seismograph is a
record of the energy from an earthquake as the waves travel through bedrock. When you triangulate the
data from three seismographs, you find the epicenter of the earthquake.
How to find an epicenter:
1. Find the delay time between the P-wave arrival and the S-wave arrival.
2. Using the scrap piece of paper method on the “P and S wave Time-Travel” graph, use the delay
time to determine the distance from the seismograph to the epicenter.
3. Use a compass to measure the distance on the map.
4. Draw a circle around the location of the seismograph at the appropriate distance.
5. After you do this for all three seismic stations, the three circles will intersect at the epicenter. If
they do not intersect, find the place where they come close to intersecting and label it as the
epicenter.
Sample Regents Questions