Seismogenic Patches in a Tectonic Fault Interface

Tectonic faults show rheological heterogeneity in interfaces, and the spectrum of their sliding regimes span a continuum from slow-slip events to dynamic ruptures. The fault interface is crucial for mechanics faulting. By using earthquake source locations, complex structure can be reproduced at resolution down 50–100 m. Here, we use declustered seismic catalog Northern California investigate structures 11 segments San Andreas, Calaveras, Hayward faults. cumulative length all about 500 km. All selected belong subvertical strike–slip A noticeable localization sources near cores observed segments. projection plane shows severe inhomogeneity. Topologically dense clusters (seismogenic patches (SPs)) detected planes. longer observation are, more distinct are clusters. SPs usually cover 10%–20% area. It vicinity that earthquakes magnitudes above 5 initiated. Voronoi tessellation used determine orderliness SPs. Distributions areas cells obey lognormal law, value entropy 1.6–1.9 prevails. findings informativeness background seismicity revealing heterogenous tectonic interface.