Answer Key for Restless Earth Study Guide
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1) Complete the study guide using your notes—just copying information from the answer key is not a very effective
way to review.
2) Check your work with this answer key and make corrections or add detail.
3) Study anything that is incorrect or you had add information to.
4) Give your corrected study guide to another person and have them quiz you. Review any information that you still
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1 .Complete the plate boundary chart below
Plate Boundary
Divergent
Movement (draw arrows)
Features (mountains, valleys, trenches, mid ocean ridge...)
Continental-continental:
Rift, volcanoes
Oceanic-oceanic:
Ridge (underwater mountains)
Convergent
Continental-continental (collision):
mountains, earthquakes
Continental-oceanic (subduction):
Volcanoes, trench, earthquake, mountains
Oceanic-oceanic (subduction):
Volcanic islands, trench, earthquake
Transform
Features: Earthquakes
2) Define subduction. Explain what happens to the crust.
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The process in which one plate slides under another plate
Occurs at convergent plate boundaries
The crust of the plate being subducted melts
2. Draw and label an example of sea floor spreading (be sure to include molten material, mid ocean ridge, old
crust, new crust).
Mid Ocean Ridge
Molten Material
4. Describe the movement of the continents from the landmass Pangaea, to their present location today, and
how they will be situated in the future.
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All of the continents used to be together in one big supercontinent (Pangaea).
Then continental drift occurred, and the continents split apart.
They are still moving away from each other, but one day, they will all come together again to form another
supercontinent
5. Draw and label convection currents in the mantle. Describe how they affect the movement in Earth’s crust.
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The hot core heats the bottom of the mantle, causing material there to rise toward the crust.
As it reaches the crust, it cools, and then sinks back down to the core.
This causes the tectonic plates to move.
6) Explain three types of evidence that support the theory of continental drift.
Type of
Description of the Evidence
Evidence
Explanation of how the Evidence Supports
Continental Drift
Fossils
Fossils from reptiles that couldn’t swim have
been found on continents that are now
separated by oceans
All the continents must have been together
since the reptile are unable to cross oceans
Land forms
Mountain ranges in South America and
Africa lined up
The location of the mountain ranges and coal
fields are evidence that all the continents
(South America, Africa, North America and
Europe used to be together)
Coal fields in Europe and North America
lined up
Climate
Glacial scarring (scratches in rocks from
glaciers) in South Africa
Glacial scarring suggests that South Africa
used to be closer to the South Pole and that
the continents have moved
Tropical plant fossils found in on Spitsbergen
(a country located north of Norway)
Tropical plant fossils in Spitsbergen suggests
that it used to be closer to the equator and
that the continents have moved
7. Use the maps to describe the global placement of volcanoes and earthquake epicenters.
Earthquake Epicenters
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Volcanoes
Most volcanoes and earthquakes occur at plate boundaries (where two plates come together).
Only a few occur in the middle of plates (hotspots)
8) Locate the Hawaiian Ridge and Emperor
Seamounts (that were formed by the same hot spot
under the lithosphere) and put a star (*) by each.
9) Draw an arrow that shows the movement of the
Hawaiian Ridge, and a separate arrow that shows the
movement of the Emperor Seamounts.
10) Explain the change in direction of the land forms.
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
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The volcanoes changed directions because the
plate moved
The hot spot that caused the volcanoes does
not move
This is evidence that plates move
C
A
B
12) Describe the characteristics of each
type of wave.
P Wave (primary): Fastest, moves back and
forth, travels through solids and liquids
S Wave (secondary): Slower than P waves,
moves side to side, only moves through
solids
L Wave (surface): Slowest waves, moves up
and down, causes the most damage.
11) Label the waves on the seismogram.
A = P Wave (Primary)
B = S Wave (Secondary)
C = L Wave (Surface)
13) What can scientists learn when they triangulate this data (get it from three different locations)?

Scientists can use seismograms to determine the location of an earthquake and the earthquake’s
magnitude (the number on the Richter Scale)
14) Describe what generally happens to an earthquake’s intensity the farther you move from the epicenter.

As you move away from the epicenter, the intensity tends to decrease.
15) List factors that would explain a lower intensity closer to the epicenter.
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If you live in a house built on solid ground, like bedrock, the intensity (strength of shaking) of an
earthquake might be lower.
If you live on loose soil or sand, the intensity might be higher.
16) Use the graph below to answer the following:
a)
b)
c)
d)
What wave travels fastest? P Wave
How long does it take a P-wave to travel 2000 miles? ~6 minutes
How long does it take an S-Wave to travel 2000 miles? 11 minutes
What is the interval between when the first P-waves arrive and the first S-Waves arrive? ~5 minutes
17) Define: volcanism
 The process of making volcanoes
 A volcano is a weak spot in the earth’s crust where magma comes up to the surface
 Most volcanoes occur along diverging plate boundaries (such as the mid-ocean ridge) or in subduction
zones around the edges of oceans (Ring of Fire)
18) Circle all the landforms that are the result of magma and erosion working together?
dikes
sills