![]() ![]() The greater accuracy of the M wg scale over the M w scale at different magnitudes (i.e., m b or M s) is found to be statistically significant in the range including smaller and intermediate events. The M wg scale is also valid for 3.5 ≤ m b ≤ 7.0 because the relations between seismic moment and the magnitudes m b and M wg are same. To improve upon the consistency of the M w scale for a wider range, a uniform generalized seismic moment magnitude scale M wg = log M 0 / 1.36 − 12.68, for magnitudes ≥ 4.5, has been developed, considering 25,708 global earthquake events having m b and M 0 values from ISC and Global CMT databases, respectively, during the period 1976–2006. We first investigate the degree of closeness of M w values with other observed magnitudes (e.g., M s and m b) for smaller and intermediate magnitude ranges considering global International Seismological Centre (ISC) and Global Centroid Moment Tensor (CMT) databases. ![]() In this study, an endeavor has been made to extend the moment magnitude scale to include lower and intermediate magnitudes in a global context emphasizing the use of body waves, particularly P waves, in which data are abundant. ![]() The formulation and validation of the M w scale were carried out considering the southern California region for lower and intermediate earthquakes. The moment magnitude ( M w) scale has been referred to by various researchers as the best scale, one that matches well with the observed surface‐wave magnitudes with M s ≥ 7.5 at a global level. Although a reliable and standardized estimation of earthquake size is a basic requirement for all tectonophysical and engineering applications, different magnitude scales estimate different values for the same earthquake, thereby making such studies inadequate. The aim of obtaining a single scale for earthquake magnitudes has led many studies in the past to either develop relationships among various existing scales or develop an altogether new scale to represent a wide range of magnitudes on a single scale. ![]()
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