Module 6: Lesson 3

 

Self-Check 4

1. “Your Turn” from “Example 5” on page 379 of the textbook.
   
   The following equations can be used to compare the intensities of the two earthquakes:
   
   
    
   
   
   Because the question is asking to compare the difference in magnitude, the equations can be rewritten like so:
   
   
    
   
   
   This can then be rearranged.
   
   
    
   
   
   Rearrange this into exponential form.
   
   
    
   
   
   By realizing that the amplitude of the second earthquake will be a reference point, the following values are known:
   
   
    

   M1 = 9.5

   
   
    

   M2 = 8.1
   
   

    

   A = ?
   
   

    
   A2 = 1
   
   Thus,
   
   The first earthquake was 101.4, or approximately 25.1, times more intense than the second earthquake.

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