Interdependency amongst earthquake magnitudes in Southern California

Recent research has shown that for the larger earthquakes recorded ( $ M\ge 5.2 $ M≥5.2) within the global centroid moment tensor (gCMT) there is a positive correlation between the magnitudes of earthquakes and the magnitudes of their aftershocks [13]. Through a modification of model independent stochastic de-clustering [12] and a more localized catalog provided by the Southern California Earthquake Data Center (SCEDC), the methodologies of Nichols and Schoenberg can be extended to catalogs complete with a much lower minimum magnitude of completeness ( $ M\ge 2.2 $ M≥2.2). Results indicate that the positive correlation observed between larger earthquakes in the gCMT catalog and their aftershocks is also evident in the relationship between the magnitudes of earthquakes in the SCEDC data and their aftershocks. However, with the lower minimum magnitude of completeness found in the SCEDC catalog and with short periods of extreme earthquake activity evident within the data, the statistical power of the stochastic de-clustering algorithms to distinguish between mainshocks and aftershocks is diminished.