On April 18 1906 an earthquake killed over 3000 people when
On April 18, 1906, an earthquake killed over 3,000 people when it hit San Francisco, with a magnitude of 8.3 on the Richter Scale. On March 11, 2011 the “Tohoku” earthquake hit central Japan with a magnitude of 9.0 on the Richter Scale, and killed 15, 894 people. How much greater was the 2011 earthquake than the 1906 earthquake?
Solution
The formula of magnitude of earthquake is
M=log(I/S)
I is the intensity of the earthquake And S is the intensity of the standard earthquake
8.3 = log(I1/S) and 9= log(I2/S)
9-8.3= log(I2/S) -log(I1/S)
.7= log(I2/I1)
I2/I1=10.7
I2=5 I1
Therefore the earhquake occurs in 2011 is 5 times more intense as compared to earthquake occurs in 1906
