Seismotectonics of the California-Baja California region.

Erik E. Ramírez-Ramos, Joann M. Stock, Zachary E. Ross, Antonio Vidal-Villegas, & Jorge Ramírez Hernández

Published August 15, 2021, SCEC Contribution #11453, 2021 SCEC Annual Meeting Poster #217 (PDF)

Mapped and unknown faults in the northern Baja California region have generated earthquakes of high magnitudes, which have caused significant damages to the infrastructure, water canals, croplands, etc. For this study, we build a new seismic catalog, from 2012 to 2020, based upon the data recorded by the seismic networks that work in the California-Baja California, Mexico, border region using deep learning techniques for the eventual 3-D fault geometry characterization. We used the waveforms from the broadband stations of the Northwest Mexico Seismic Network (RESNOM) alongside those stations close to the border belonging to the Southern California Seismic Network (SCSN). The nine-year database started in 2012, the approximate year when the instruments were upgraded and RESNOM coverage improved (after the 4 of April 2010 El Mayor-Cucapah earthquake). To improve the characterization of small earthquakes (M<1.5), we analyzed the waveforms using deep learning to detect P and S arrivals, of the combined database, alongside the association phase detection-earthquake (PhaseLink). After the deep learning analysis, we locate the hypocenters using Non-Linear Locations and relocate them using the source-specific station term method. Yearly-base catalogs resulting from the phase detection and association and the hypocentral locations and relocations have 2-4 times more earthquakes than the number of events reported by the RESNOM catalogs for the same annual period. Complete the catalog for the California-northern Baja California border region with small earthquakes and precise hypocentral locations will help constrain the active-faults geometry, including areas with no surface faults or ruptures that have been reported.

Key Words
Baja California, RESNOM, seismicity

Citation
Ramírez-Ramos, E. E., Stock, J. M., Ross, Z. E., Vidal-Villegas, A., & Ramírez Hernández, J. (2021, 08). Seismotectonics of the California-Baja California region.. Poster Presentation at 2021 SCEC Annual Meeting.

Related Projects & Working Groups
Seismology