Paleoseismic analysis of the San Vicente segment of the El Salvador Fault Zone, El Salvador, Central America
Canora, Carolina (Universidad Complutense de Madrid. Departamento de Geodinámica, Estratigrafía y Paleontología)
Villamor, P. (GNS Science)
Martínez Día, J. J. (Universidad Complutense de Madrid. Departamento de Geodinámica, Estratigrafía y Paleontología)
Berryman, K. R. (GNS Science)
Álvarez Gómez, José A. (Universidad de Cantabria. Instituto de Hidráulica Ambiental)
Capote, Ramón (Universidad Complutense de Madrid. Departamento de Geodinámica, Estratigrafía y Paleontología)
Hernández, W. (Servicio Nacional de Estudios Territoriales (El Salvador))

Data:	2012
Resum:	The El Salvador earthquake of February 13th 2001 (Mw 6. 6) was associated with the tectonic rupture of the El Salvador Fault Zone. Paleoseismic studies of the El Salvador Fault Zone undertaken after this earthquake provide a basis for examining the longer history of surface rupturing earthquakes on the fault. Trenching at five sites along the San Vicente segment, a 21km-long and up to 2km-wide central section of the El Salvador Fault Zone, shows that surface fault rupture has occurred at least seven times during the past 8ka. Single-event displacements identified at each trench vary from several decimetres to at least 3. 7m. Fault trace mapping, geomorphic analysis, and paleoseismic studies indicate a maximum magnitude for the El Salvador Fault Zone is c. Mw 7. 6, with a recurrence interval of around 800yr. Earthquakes of Mw 6. 6 or smaller, such as the February 2001 event are unlikely to be identified in the paleoseismic trenches, so our observations represent the minimum number of moderate to large earthquakes that have occurred on this part of the El Salvador Fault Zone. We observe significant variability in single-event displacement in the trenches, which we interpret as possible cascade rupture of several segments of the El Salvador Fault Zone. Combining displacements of river courses and the timing of events revealed in the trenches, we calculate a slip rate of c. 4mm/yr for El Salvador Fault Zone, identifying the fault zone as a major tectonic feature of the region, and a major source of seismic hazard and risk in El Salvador.
Drets:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan aquestes es distribueixin sota la mateixa llicència que regula l'obra original i es reconegui l'autoria de l'obra original.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Matèria:	El Salvador Fault Zone ; Active fault characterisation ; Strike-slip fault ; Volcanic arc ; Paleoseismic studies
Publicat a:	Geologica acta, Vol. 10, Núm. 2 (June 2012) , p. 103-123, ISSN 1696-5728

Adreça alternativa: https://raco.cat/index.php/GeologicaActa/article/view/257168
Adreça alternativa: https://revistes.ub.edu/index.php/GEOACTA/article/view/105.000001700
DOI: 10.1344/105.000001700

21 p, 2.5 MB

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