A magnitude 8 earthquake is 1,000 times more intense than a magnitude 5 earthquake.
B
A magnitude 8 earthquake is 108 times more intense than a standard earthquake, while a magnitude 5 earthquake is 105 times more intense than a standard earthquake, and 108 ÷ 105 = 103.
C
Each unit increase on the Richter scale corresponds to an intensity increase by a factor of 10. So from 5 to 8 on the Richter scale, the intensity increases by 103 = 1,000