Relocation and seismotectonic interpretation of the seismic swarm of August - December of 2012 in the Linares area, northeastern Mexico

Abstract

We relocated 52 events of 2.5 ≤ Mc ≤ 3.6 from a seismic sequence of over 250 events that occurred during July-December 2012 southwest of the Linares area, northeastern Mexico. To examine this swarm four seismic stations were installed in the region and operated during different time periods from September to December. Relocation of the swarm showed that the earthquake hypocentral depths were at 8 (±5) km, and the time residuals had values ≤ 0.38 s. The fault plane solutions were generated for individual earthquakes and through the use of the composite mechanism technique. The focal mechanism solutions show pure reverse faulting; the SW dipping NNW - SSE trending nodal plane is the inferred fault plane (strike ~150°, dip ~50° and rake ~67°), which reveals that maximum horizontal stress (SHmax > Shmin > Sv) predominates in the area.

An earthquake focal mechanism catalog for source and tectonic studies in Mexico from February 1928 to July 2022

“…In our catalog, tectonic earthquakes comprise 7459 focal mechanisms reported in previous studies and for different seismological observatories using different data and methods (Molnar and Sykes, 1969;Thatcher and Brune, 1971;Molnar, 1973;Johnson et al, 1976;Jimenez-Jimenez, 1977;Dean and Drake, 1978;Ebel et al, 1978;Jimenez and Ponce, 1978;Kanamori and Stewart, 1978;Yamamoto, 1978;Reyes et al, 1979;Astiz, 1980;Morales-Matamoros, 1980;Zúñiga and Valdés-González, 1980; Chael and Stewart, 1982; Frohlich, 1982;Natali and Sbar, 1982;Domínguez-Reyes, 1983;Havskov et al, 1983;Astiz and Kanamori, 1984;Beroza et al, 1984;Burbach et al, 1984;González and Suárez, 1984;González et al, 1984;Lesage, 1984;Munguía and Brune, 1984;Yamamoto et al, 1984;LeFevre and McNally, 1985;Singh et al, 1985;González-Ruiz, 1986;Mota-Palomino et al, 1986;Ruiz-Kitcher, 1986;Suárez and Ponce, 1986;Yamamoto, 1986;Goff et al, 1987;González-Ruiz, 1987;Yamamoto and Mota, 1988;Yamamoto and Mitchell, 1988;Domínguez-Rivas, 1991;Doser, 1992;...…”

“…In light of the relevant seismic hazard in the region and its importance from the geodynamical perspective, many authors have computed the focal mechanisms of seismic events using different data and several techniques (e.g., Molnar and Sykes, 1969;Dean and Drake, 1978;Chael and Stewart, 1982;LeFevre and McNally, 1985;Goff et al, 1987;Doser and Rodriguez, 1993;Pacheco et al, 1993;Pardo and Suárez, 1993;Pardo and Suárez, 1995;Quintanar et al, 1999;Rebollar et al, 1999;Quintanar et al, 2004;Rodríguez-Lozoya et al, 2008;Ortega and Quintanar, 2010;Pacheco and Singh, 2010;Sumy et al, 2013;Dougherty and Clayton, 2014;Abbott and Brudzinski, 2015;Rodríguez-Pérez and Singh, 2016;Huesca-Pérez et al, 2022). National and international observatories also provide focal mechanism solutions for seismic events generated in the territory of Mexico (e.g., the Mexican Seismological Service, SSN; the Southern California Seismic Network, SCSN; U.S. Geological Survey, USGS).…”