Seismic energy radiated by earthquakes in the Basin and Range Province of Sonora, Mexico, near the rupture of the 1887 Mw 7.5 earthquake

• Published in: Journal of seismology 2021-02, Vol.25 (1), p.73-83
• Main Authors: Castro, Raúl R., Villalobos-Escobar, Gina P.
• Format: Article
• Language: English
• Subjects: Earth and Environmental Science; Earth Sciences; Earthquakes; Energy; Fault lines; Fault location; Geological faults; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Hydrogeology; Original Article; Rupture; Rupturing; Seismic activity; Seismic energy; Seismograms; Seismology; Structural Geology; Tectonics
• ISSN: 1383-4649; 1573-157X
• DOI: 10.1007/s10950-020-09953-0

We estimated the seismic energy radiated by 47 earthquakes located near the faults that rupture during the 3 May 1887 Mw 7.5 Sonora earthquake in the Mexican Basin and Range Province. We retrieve source parameters from seismograms recorded by the local network RESNES ( Red Sismica del Noreste de Sonora ) that operated from 2003 to 2011, using a spectral inversion technique. We calculated the seismic energy by integrating the square velocity source spectrum of the earthquakes analyzed. We found that events with high-scaled seismic energy ( E s / M o ) are located at the southern end of the fault that rupture in 1887, between the stepovers of the fault segments Teras and Otates. It is likely that tectonic stress accumulated in that zone after the fault ruptured. We estimate an average log( E s / M o ) = − 5.76 and found that most earthquakes analyzed have low apparent stress, varying between 0.5 × 10 −3 and 1.85 MPa, with an average value of 0.0521 MPa. The apparent stress is heterogeneous not showing a clear correlation with seismic moment or focal depth.