The Richter scale assesses the 1906 San Francisco earthquake and the 1964 Alaska earthquake as both being of magnitude 8.3.However,on the moment magnitude scale,the San Francisco earthquake is probably equivalent to a Richter magnitude 7.8 and the Alaska seism is equivalent to a 9.2.The Alaska earthquake was at least 100 times bigger.

Question

Quizplus · Accepted Answer

The statement is true. The Richter scale is based on the amplitude of waves recorded on a seismogram, while the moment magnitude scale takes into account the size of the fault rupture, the amount of slip, and the rock stiffness. The San Francisco earthquake had a smaller fault and less slip compared to the Alaska earthquake, which is why it is assessed as a lower magnitude on the moment magnitude scale.

The Richter Scale Assesses the 1906 San Francisco Earthquake and the 1964