Stress drop in earthquakes

Abstract

abstract A correlation is made between earthquake magnitude and parameters of fault trace on the basis of dislocation theory. For earthquakes with magnitudes M between 5.5 and 8.5, the correlation with fault length L and the maximum horizontal or vertical offset D (both in cm) is approximately log L D 2 = 2.24 M − 4.99. Combining this result with a magnitude-energy formula, it is found that the stress drop is dependent upon magnitude, with the fractional stress drop increasing with magnitude.