e-binder for 2013 CEETEP workshop
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b. Continental spreading centers include the
__________________ in the US and the _______________________ in Africa.
6. Convergent margins – subduction zones:
Identify the land form (geomorphology) created at each type of Convergent Boundary
and provide an example.
Ocean-Ocean _____________________________________________________a.
Ocean-Continent __________________________________________________b.
Continent-Continent ________________________________________________c.
7. Transform faults – strike slip faults
a. Sometimes tectonic plates shift past each other horizontally ________________
directions at their boundary.
b. One example of a strike slip fault near San Francisco is the _________________.
8. Earthquakes:
Most earthquakes occur near plate _____________.a.
_____________ keeps the plate edges from sliding smoothly past each other.b.
The longer the plates remain stuck, the more strain builds and the more violent c.
the snap and resulting _____________.
9. Volcanoes:
a. Magma rises to the surface from inside the earth mainly at __________________
and _______________________.
Around the rim of the Pacific Ocean, the 40,000 km long ________ of ________ b.
is especially active.
10. Hot Spots:
In a few places _________ melts through a tectonic plate.a.
Each hot spot likely marks the top of a plume of _____________ rock that risesb.
from deep in the earth.
Discussion Questions: (italics are guiding ideas on a few random questions.)
Discussion questions can be used in a whole group setting, or selected questions may be assigned to table groups
to answer and then shared with the class.
1. Does the location of earthquakes and volcanoes show a pattern? If so, what tectonic process may be responsible?
(compression, extension, shearing)
2. Generally speaking, where are the oceanic ridges located with respect to the landmasses?
(in the middle of the ocean:
heavy thin crust sinks and water fills low areas.)
3. Where do you find the mountain ranges with respect to the oceanic ridges? Use examples. (the ocean-floor ranges are
on the crest of the spreading ridges where heat provides the buoyant lift; they sink as they cool.)
4. Are there any places on Earth where the mid-oceanic ridges meet the continent?
5. What are seamounts?
6. Most of the Pacific Ocean is on what plate?
7. What is the compass orientation of the Hawaiian Islands and many of the other smaller ridges within the Pacific
Ocean? Is this significant? (the islands are moving away from the hotspot in the direction the plate is traveling. Thus the line
of the youngest islands is oriented west-northwest as they move towards Japan)
8. In what compass direction is the Pacific Plate moving? (see previous question)
9. Name the biggest and longest mountain range in the world. What is it? (Trick question. It is a mid-ocean ridge.)
10. Name an island chain that has been formed by a “hot spot”. (see question 7 above. The Hawaiian Islands.)
11.What island in the North Atlantic Ocean is splitting apart? What is causing the split? (Iceland is a hotspot that is
straddling the Mid-Atlantic spreading ridge. The spreading ridge is causing the split. If it were just a hotspot it would just build a
big edifice.)
12. Where is magma rising to the surface and forming ocean crust? (At spreading ridges)
Where is the oceanic crust sinking back into the mantle? (At subduction zones)
13. Some people have referred to the process in the above question as a cycle. Why would it be considered a cycle?
(Rock is formed at the spreading ridge; gets destroyed at subduction zones. The subducted rock eventually gets absorbed into the
mantle and gets caught in the very slow circulation of rock in the mantle which can melt as it rises to the top again.)
14. What are the attributes of a cycle?
Can you describe another cycle that could compare with the example described above.
15. Why is it that the Pacific Ocean floor is no older than about 200 million years and yet the continents are much
older? (The ocean floor is being created constantly. It is made of heavy rock that tends to subduct when it meets continental
rock. The continents are made of older rock that is more buoyant .
16. The continental margins of the East and West Coast of the United States are very different. Describe the
differences. Are there tectonic differences?
17. Where would you expect to find igneous, sedimentary and metamorphic rocks?