A seismotectonic analysis of the Anza seismic gap, San Jacinto fault zone, southern California ( USA).

Abstract

Small earthquake epicenters near the Anza seismic gap define a 20-km quiescent segment of fault bounded to the NW and SE by areas of relatively high seismicity. The fault appears to be seismogenic and highly stressed but locked by some mechanism. A possible explanation is given. Seismicity near Cahuilla 13 km to the SW is examined and suggests that the ground beneath Cahuilla may be acting as a stress meter signaling the presence of high stresses before large local earthquakes. The length of the quiescent fault segment suggests potential for about an M 6.5 earthquake if the entire segment ruptures at once.-after Authors