plate tectonics questions

1.     What are the first 3 types of plate boundaries listed?

         

• Divergent boundaries -- where new crust is generated as the plates pull away from each other.
• Convergent boundaries -- where crust is destroyed as one plate dives under another.
• Transform boundaries -- where crust is neither produced nor destroyed as the plates slide horizontally past each other.

2.     What does the word divergent mean in regard to plate movement?  What forces the plates to move apart at divergent boundaries?

Means that plates are moving apart and the force pushing up the plates is caused by magma pushing up from the mantle.

3.     Give an example of a specific mid-ocean ridge where seafloor spreading and divergent boundaries occur.  What country sits directly on top of this ridge?  What are the red triangles         that are shown on the map of this country?

The southern tip of Africa lies on top of this ridge.

red triangles are inactive volcanoes.

Mid-Atlantic Ridge averages about 2.5 centimeters per year (cm/yr), or 25 km in a million years

4.     What does the word convergent mean in regard to plate movement?

The plate is making a slow collision and they are overlapping each other

5.     Find the diagrams shown on the website for each of the following kinds of plate boundaries.  Label and post the three diagrams on your blog.

a.     Oceanic-continental convergence

b.     Oceanic-oceanic convergence

c.     Continental-continental convergence

 

6.     When one plate gets pushed below another plate it is called subduction.  What geologic features form on Earth’s surface directly above the subduction zone in the case of:

a.     oceanic-continental convergence?
A number of long narrow, curving trenches form and are thousands of kilometers long. These trenches are 8 to 10 km deep cutting into the ocean floor.
b.     oceanic-oceanic convergence?
 When two oceanic plates converge, one plate is usually subducted under the other plate, and in the process which trenches formed. This can also result in the formation of underwater volcanoes.
c.     continental-continental convergence?
 When two continental plate converge they make a mountain ridge like the Himalayas when the Indian and Eurasian plates had a collision.

 

7.     What is a transform boundary?  What geological disturbance is caused along transform boundaries?  Where in North America is there an example of this type of plate boundary?
A transform boundary is the zone between two plates sliding horizontally past one another. The geological disturbence caused be the transform boundaries is that Canadian geophysicist J. Tuzo Wilson, concept that transform faults were that large faults or fracture zones connect two spreading centers. The San Andreas fault zone in California is an example of these plates in North America. 

 

8. Using the Internet and a focused search, identify the type of plate interaction that caused the following features:

a. Mid-Atlantic Ridge

divergent plate boundary plates/ Oceanic-Oceanic

b. Kuril Trench

Convergent boundaries plates/ Oceanic-Oceanic

c. Phillipine Islands

Convergent boundaries plates/ Oceanic-Oceanic

d. East African Rift Valley

Divergent boundaries plates/Continental-Continental

e. Red Sea

Divergent boundaries plates/Continental-Continental

f. Peru-Chile Trench

Convergent boundaries plates/Oceanic-Oceanic

g. Aleutian Islands

Convergent boundary plates/ Oceanic-Oceanic

geologic timeline follow up q's

(1) Air in the atmosphere would have had to be there for animals to survive. Also weather that could support life. And lets not forget food or the thing we can't survive without.
(2) The Archaean eon because that is the eon when the earth is forming. But if the earth didn't form nothing would be here. So the Archaean is the most important period.
(3)The human existence is not very significant. We are only a small part of the history of earth. For example if you had a 4.5 meter long paper with each meter representing a billion we would be a very very small part of the paper.