For the moment magnitude scale, each increase on the scale represents 31.5 more energy released by the earthquake. Which is a good estimate of how much more motion is there for a magnitude 7 earthquake than a magnitude 4 earthquake?
A. 90 times
B. 27,000 times
C. 900 Times
D. 3000 times

27,000

Explanation:

The provided statement talks about an estimate of energy release by an Earthquake with a magnitude of 4 to a magnitude of 7. According to the statement, for the moment magnitude scale, 31.5 times more energy is released with increase of one magnitude scale. Therefore, if we take a rounded value of 31.5 as 30 and multiply it three times (30 X 30 X 30) to represent 3 scales (4 to 7) on moment magnitude scale, we will get 27,000 times more energy.