The Strongest Possible Earthquake Ground Motion

Ground accelerations have been seen to exceed three accelerations of gravity (g). Can extreme motions further surpass this level as more earthquakes are experienced? Also, ground shaking of nearly same severity has been observed near earthquakes differing in magnitude by three units. Does this imply independence of extreme shaking on magnitude? Calculations based on the representation theorem of elasticity verify that maximum ground accelerations on bedrock even for the greatest magnitudes saturate at the level of approximately 3 g. Maximum ground velocities approach the values of 2 m/s. Also, the peak level of extreme shaking is nearly independent of magnitude.