How is Moment Magnitude (MW ) calculated?
A) from average fault displacement, average fault rupture area, and rock shear strength in the fault zone or by measuring very long period waves on special long period seismometers, triggered to record only very large earthquakes
B) from surface wave magnitude measured one minute after the first P- wave arrival
C) from the amount of building or other infrastructure damage in large earthquakes with more than one minute of of ground shaking
D) from S- wave magnitude measured one minute before the last P- wave arrival

Question

Quizplus · Accepted Answer

The Moment Magnitude (MW) scale is calculated either from the seismic moment, which involves the average fault displacement, average fault rupture area, and the rock shear strength in the fault zone, or by measuring very long period waves on special long period seismometers, which are triggered to record only very large earthquakes. This method provides a more accurate and scalable measure of earthquake size, especially for very large earthquakes, compared to other magnitude scales.

How Is Moment Magnitude (MW ) Calculated