Distribución espacio-temporal de la sismicidad sentida en Costa Rica (1976-2013) en el marco histórico del 30 aniversario (1982-2012) de la Red Sismológica Nacional (RSN: UCR-ICE)

Abstract

ABSTRACT:The National Seismological Network of Costa Rica (RSN) was created in 1982 through an agreement between the Central American School of Geology of the University of Costa Rica and the Costa Rican Institute of Electricity. In this paper, we present a short review of the RSN contributions in Seismology to the Journal of Geology of Central America (RGAC) that is expressed in 63 publications. We also analyze the geographic and temporal distribution of 3363 earthquakes reported by the RSN through media reports and RGAC publications during 1976-2013. During the analyzed period the annual average of felt earthquakes in Costa Rica was 90, five 5.0-5.9-magnitude earthquakes were felt on average every year, and one 6.0-6.9-magnitude earthquake were felt every two years. Five earthquakes had a magnitude greater than 7.0 including the 1991 Limón (7.7 M w ) and 2012 Samara (7.6 M w ) earthquakes. The majority of felt earthquakes (83,7%) had depths of less than 30 km. The seismogenic sources with the greatest energy release were the shallow processes related to the subduction of the Cocos Plate (54.5%) and the North Panama Deformed Belt (38,7%).

Preliminary Results of an Earthquake Early Warning System in Costa Rica

“…With the examples presented here, where alerts have been provided within 11 s of event initiation, we can expect late alerts for all shallow crustal events within 40 km of the capital. Unfortunately, if the present network delivers EEW, this would mean late alerts for repeats of some historically destructive events near San Jose, such as the Cartago earthquake (M 6.4) in 1910 (Montero and Miyamura, 1981) and the Cinchona earthquake (Mw 6.1) in 2009 (Linkimer and Alvarado, 2014), which were originated by local faults with epicenters at 20 and 30 km of the city, respectively. The alert time is modest (<5 s) for seismic events close to San Jose originated in the subduction zone, such as the 1990 Cobano (Mw 7.0) and 1999 Quepos (Mw 6.9) earthquakes, and at intermediate depth in the subducting slab, like the 1992 Naranjo earthquake (Mw 6.5).…”

“…This complex tectonic setting generates high-seismicity rates. Since 1821, the nation has faced 68 damaging earthquakes, with an average rate of one every three years (Montero, 1989;Peraldo and Montero, 1994;Linkimer and Alvarado, 2014).…”

Distribución geográfica de los sismos contenidos en el catálogo de la Red Sismológica Nacional de Costa Rica

“…Por esta razón, la cantidad y densidad de sismos por cantón no necesariamente corresponde con una mayor percepción de la sismicidad en dichas zonas. En relación con los sismos que han sido reportados como sentidos a la RSN (Linkimer y Alvarado, 2014), los cantones de Pérez Zeledón, Turrialba y El Guarco han sido el escenario de la mayor cantidad de estos sismos sentidos. Esto concuerda con los resultados obtenidos que muestran que, Pérez Zeledón y Turrialba son cantones con alta cantidad de sismos y El Guarco un cantón con una densidad de sismos alta (Figura 4).…”

Revista Completa

“…Esta situación obedece a su ubicación en una zona de subducción en donde interactúan cuatro placas tectónicas: Coco, Caribe, Nazca y Panamá (figura 1). Desde 1821, el país ha sufrido el embate de 68 terremotos, 20 de los cuales han tenido magnitud mayor a 7,0 (Montero, 1989;Peraldo y Montero, 1994;Linkimer y Alvarado, 2014). Entre los terremotos más recientes, se pueden contar el de Cinchona en el 2009 (magnitud 6,1) y el de Nicoya en el 2012 (7,6).…”