An Earthquake Catalogue for El Salvador and Neighboring Central American Countries (1528-2009) and Its Implication in the Seismic Hazard Assessment

Abstract

Merging all available databases, a comprehensive and updated earthquake catalogue for El Salvador and surrounding areas has been compiled, containing a total of 2,584 events for the period 1528-2009, covering the geographic window delimited by the coordinates 11.0°-16.5° N and 85.5°-92.0° W, focal depths of 0.0 to 304 km, and the moment magnitudes in the interval 5.0 ≤ M W ≤ 8.1. Events in the catalogue are distributed into six seismogenic sources taking into consideration the tectonic regime affecting El Salvador, the interplay and complexities between shallow crustal, intraplate and interface subduction seismicity has been thoroughly investigated, primarily with the aim of developing detail criteria to delimit the seismogenic sources in order to perform a consistent seismic hazard assessment. A uniform hazard spectrum for San Salvador and seismic hazard maps and their uncertainty have been calculated for the horizontal component of ground motion for rock site conditions using zone and zone free methods. The references cited in the article constitute a comprehensive list of sources of information on the tectonics and seismicity of El Salvador and neighboring Central American countries.

Perspective Chapter: Testing the Interoccurrence Times Probability Distributions of Earthquakes

“…Indeed, each region should have its declustering dynamic window on time and space that belongs to the tectonics of the region under study. We conclude that the catalog declustering process is necessary when employing the classical Cornell seismic hazard assessments on time-independent schemes as previous works have applied for the region [6,[29][30][31]. In other words, despite the Poisson probability distribution not fitting the natural seismicity of subduction earthquakes, the declustering process produces a Poisson distribution with only independent events.…”

“…We updated the homogenized moment magnitude catalog of Salazar et al [6] using online global information as the International Seismological Centre ISC [7], the Preliminary Determination of Epicenters PDE [8], the Centroid Moment Tensor solutions [9], and detail-oriented studies for earthquake locations of large earthquakes [3,4,[10][11][12]. The catalog covers the geographical window between 11 and 16.5 0 N and 85.5-92 0 .…”

“…Note that earthquakes from other regional seismogenic sources (e.g., volcanic chain, Guatemalan faults, and Honduran-Guatemalan Grabens) were also compiled; however, this study is devoted to only subduction events. Salazar et al [6] present the criteria to separate upper-crustal and subduction events based on geological and focal mechanism information. We also applied the Gardner and Knopoff [14] method to extract the main events from the original catalog, eliminating the foreshocks and aftershocks.…”

Integrated Seismic Catalog for Colombia

“…For the homogenization/standardization of magnitudes to moment magnitude (M w ), we use the relationships proposed by Arcila et al (2020) for M L , m b and Ms and the relationship proposed by Salazar et al (2013) for M d from the CASC catalog. For this particular case, only solutions with a standardized M w value greater than or equal to 3.5 were considered.…”