Detection of earthquake swarms at subduction zones globally: Insights into tectonic controls on swarm activity

摘要: Earthquake swarms are characterized by an increase in seismicity rate that lacks a distinguished mainshock and does not obey Omori's law. At subduction zones, they thought to be related slow-slip events (SSEs) on the plate interface. zones can therefore used as potential indicators of events. However, global distribution earthquake at remains unclear. Here, we present method for detecting such sequences using space–time epidemic-type aftershock-sequence (ETAS) model. We applied this (M ≥ 4.5) recorded ANSS catalog during period 1995–2009. detected 453 swarms, which is about 6.7 times number observed previous catalog. Foreshocks some large earthquakes also swarms. In Ibaraki-Oki, Japan, swarm-like foreshocks ordinary repeatedly occur same location. Given both SSEs interface, these regions may have experienced recurring SSEs. then compare swarm activity tectonic properties finding positively correlated with curvature incoming before subduction. This result implies controlled either hydration plate, or heterogeneity interface due fracturing slab bending.