Seismicity in the Gulf of California, Mexico, in the period 1901–2018

Abstract

We compile a new catalog of earthquakes that occurred in the region of the Gulf of California, Mexico, between 1901 and 2018. We include events reported by the catalog of the seismic network RESNOM (Red Sísmica del Noroeste de México) operated by the CICESE (Centro de Investigación Científica y de Educación Superior de Ensenada, Baja California) and complemented with events listed in the ISC (International Seismological Centre) and the SSN (Servicio Sismológico Nacional, UNAM) catalogs. The minimum magnitude of completeness of this catalog is Mc = 3.6, and we find that many hypocenters concentrate between 5 km and 10 km depth, the likely depth of the seismogenic zone of the earthquakes in the Gulf of California. We identify active and inactive faults in this region, and we detected faults located approximately 300 km SE of April 2010 El Mayor-Cucapah (Mw 7.2) earthquake that were probably reactivated by this earthquake sequence. We additionally compiled a catalog of focal mechanisms and found that most strike-slip fault earthquakes are located on transform faults and normal fault earthquakes near the spreading centers. We also detected seismicity lineaments and strike-slip events off the major transform faults that tend to occur parallel to the ridge direction either at the continental crust or at the oceanic-continental transition zone as previously reported by Ortega and Quintanar (2010) in the southern gulf.