Geophysics 20 Study Questions 3

Earthquakes

  
Study Questions: Global Plate tectonics

1) What property of the earth's magnetic field has allowed scientists to 
determine the rate of spreading at ocean ridges?

2) How is the age of oceanic crust determined and why is there no oceanic
crust older than 200 M years?

3) Define crust, lithosphere and astenosphere. Approximately how thick are
plates?

4) What is the tectonic explanation for earthquakes that occur in 
California? ; in Iceland? ; in Chile?

5) What is the typical relative velocity between two plates? How do we measure
relative velocities of plates?

6) What are the characteristic features of a subduction zone?

7) What information about the motion of the Pacific Plate can be learned 
from the Hawaiian Islands?

8) What are the 4 fundamental assumptions of plate tectonic theory?