The 2010–2014.3 global earthquake rate increase

Abstract

AbstractIn light of a heightened global earthquake rate during the first quarter of 2014 and recent studies concluding that large earthquakes affect global seismicity for extended periods, we revisit the question whether the temporal distribution of global earthquakes shows clustering beyond that expected from a time‐independent Poisson process. We examine a broad window from 1979 to 2014.3 for M ≥ 7.0 shocks, and a narrow window for M ≥ 5.0 seismicity since 2010 that has higher than average rates. We test whether a Poisson process can be falsified at 95% confidence to assess the degree of dependent clustering in the catalogs. If aftershocks within at least one rupture length from main shocks/foreshocks are filtered, then we find no evidence of global scale M ≥ 5.2–5.6 (depending on parameters) clustering since 2010 that demands a physical explanation. There is evidence for interdependence below this threshold that could be a consequence of catalog completeness or a physical process.