Mid-Ocean Ridges

Mid-Ocean Ridges

NOAA Lesson 2: http://www.montereyinstitute.org/noaa/lesson02.html

Mid-Ocean Ridge Activity: Answer the following questions using complete sentences.

1. 
   What is a Rift Valley?
   

2. 
   Where is the most volcanically active region of our planet?
   

3. 
   What is a convergent boundary?
   

4. 
   What is a divergent boundary?
   

5. 
   What is the spreading rate at the Juan de Fuca Ridge?
   

6. 
   What is a hydrothermal vent?
   

Fill in the name of the 6 ridges and the location and answer questions below

7. 
   What is the age range of the crust at the ridges? ______________________________________
   

8. 
   Where is the youngest ocean floor located?___________________________________________
   

9. 
   Where is the oldest ocean floor located?______________________________________________
   

10. 
    There are rocks on every continent that are 3 to 4 billion years old. Why are there no oceanic rocks older than 200 million years?
    

11. 
    In the eastern pacific, why are oceanic rocks no older than 120 million years?
    

12. 
    Based on the distribution of color on the map, which ridge is spreading faster, the Mid-Atlantic Ridge or the East Pacific Rise?
    

13. 
    Based on the distribution of color on the map, which ridge is spreading faster, the Mid-Atlantic Ridge or the Southeast Indian Ridge?
    

14. 
    How does the rate of spreading of the southeast Indian Ridge compare to the Southwest Indian Ridge?
    

15. 
    If the mid-ocean ridges activity today continues to produce new sea floor for another 100-200 million years, how will the appearance and location of oceans and continents continue to change?
    

16. 
    Based on the diagram, how many times has the Earth's magnetic field reversed during the past four million years?
    

17. 
    Approximately when did the current interval of normal polarity begin?
    

18. 
    If there had been compasses four million years ago, which direction would compass needles have pointed?