What measure of earthquake size depends on rock rigidity, amount of slip, and area of rupture?

The seismic moment (M_0) is a comprehensive measure of earthquake size that directly incorporates critical physical parameters of the earthquake event. It takes into account the rigidity of the rocks involved, the amount of slip that occurs along the fault during the earthquake, and the area of the fault that has ruptured. This aspect makes seismic moment particularly effective in quantifying the energy release during large earthquakes and allows for a more detailed understanding of the event's characteristics.

In contrast, the Richter scale primarily measures the amplitude of seismic waves recorded by seismographs, which can sometimes lead to underestimations of larger earthquakes, especially if they generate low-frequency waves that don't correspond well with the Richter measurements. The intensity scale measures the effects of an earthquake at specific locations and how they vary with distance from the epicenter, focusing on human experience and damage rather than the underlying physical properties. The magnitude scale is a broader term that may include various scales such as the Richter scale, which does not account for the factors that the seismic moment does. Hence, seismic moment is the more accurate measure when considering the intrinsic properties of the earthquake itself.