Boletín de la Sociedad Geológica Mexicana

Volumen 78, núm. 2, A101025, 2026

https://doi.org/10.18268/BSGM2026v78n2A101025

  

Evolución temporal de la sismicidad para el lapso 1993-2024 y la amenaza sísmica del sistema de fallas de Algeciras (Colombia)

 

Temporal evolution of seismicity for the period 1993-2024 and seismic hazard of the Algeciras fault system (Colombia)

 

Germán Chicangana1,2, *, Carlos Vargas2

 

1 Grupo Geoamenazas e Ingeniería Civil, Facultad de Ingeniería Civil, Universidad Santo Tomás. 500003, Villavicencio, Colombia. 

2 Grupo de Geofísica, Departamento de Geociencias, Facultad de Ciencias, Universidad Nacional de Colombia. Ed. 224 Manuel Ancízar, 111131, Bogotá, Colombia.

 

* Corresponding author: (G. Chicangana) This email address is being protected from spambots. You need JavaScript enabled to view it.



 

How to cite this article:

Chicangana, G., & Vargas, C. (2026). Evolución temporal de la sismicidad para el lapso 1993- 2024 y la amenaza sísmica del sistema de fallas de Algeciras (Colombia): Boletín de la Sociedad Geológica Mexicana, 78(2), A101025. https:// doi.org/10.18268/BSGM2026v78n2A101025

 

Manuscript received: June 30, 2025. Corrected manuscript received: September 19, 2025. Manuscript accepted: October 6, 2025.

ABSTRACT

The Algeciras Fault System (AFS) is located in southwestern Colombia and has a total length of 420 km. The AFS is divided into two segments: a northern segment of 160 km and a southern segment of 260 km. The AFS has recorded major historical earthquakes, including the November 16, 1827 (Mw 7.1) and the February 9, 1967 (Mw 7.2) events. Seismicity variations were analyzed using data from the Colombian National Seismological Network for the period between June 1993 and March 2024. The December 24, 2019, Mw 6.0 Mesetas earthquake occurred in the northern segment. Results indicate that seismicity variations signaled the temporal proximity of this event in that segment, whereas in the southern segment, an increase in lowmagnitude earthquakes was observed from 2009 onward, attributable primarily to technical factors related to the expansion of the seismological network. Nevertheless, the AFS was found to exhibit a high rate of seismic activity; its main structure, the Algeciras Fault, produced 20 earthquakes with magnitudes ranging from 4.0 ≤ Mw ≤ 6.0 over a period of 31 years.

Keywords: Colombia, Eastern Cordillera, seismicity, GutenbergRichter law, seismic hazard.