Author Question: Although we don't know for sure, changes in the strength and orientation of earth's magnetic field ... (Read 50 times)

iveyjurea

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Although we don't know for sure, changes in the strength and orientation of earth's magnetic field are most likely due to
 
  A) fluctuations in outer-core convection.
  B) variations in sea-floor spreading rates.
  C) the total number of mantle hot spots.
  D) changes in the velocity of subducting plates.

Question 2

True or False: Mantle convection occurs because upward-moving rock expands more by decompression than it contracts by cooling.
 
  Indicate whether this statement is true or false.



ricroger

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Answer to Question 1

Answer: A

Answer to Question 2

Answer: TRUE



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