Source characteristics of the 1989 Boca del Tocuyo earthquakes in northwestern Venezuela

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Main Author: G. Suárez
Format: Artículo científico
Language:en
Published: Universidad Nacional Autónoma de México 2007
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author G. Suárez
author_facet G. Suárez
contents Source characteristics of the 1989 Boca del Tocuyo earthquakes in northwestern Venezuela G. Suárez Gustavo Malavé Ciencias de la Tierra Venezuela seismic hazard Caribbean tectonics complex seismic rupture The Boca del Tocuyo earthquake of April 30, 1989, has a special significance in assessing the seismic hazard of northern Venezuela and in understanding the complex tectonic deformation in this area. Although it was an event of moderate magnitude (Mw=6.2), the mainshock and its largest aftershock (Mw=5.6) produced considerable damage in low-rise structures, mainly due to soil failure, and induced intense liquefaction in most of the coastal towns near the epicentral area. Both earthquakes show body-wave trains which are much longer than those expected for events of such magnitude. The reason for this anomalous duration was analyzed through the formal inversion of the P, SH, and SV waves recorded teleseismically. The results show that the Boca del Tocuyo main event was generated by multiple rupture processes composed of at least two and perhaps three subevents, whereas the aftershock was formed by two subevents. Although the direction of rupture propagation could not be gleaned directly from the teleseismic body wave data, the epicentral relocation of the largest aftershock, the hypocentral distribution of about 60 aftershocks (mb<4.5), and the linearity of the coast, which is parallel to the geologic structures in this area, suggest right-lateral, strike-slip faulting in a NW-SE direction. The Boca del Tocuyo earthquakes were apparently generated on a system of conjugate faults that are oblique to the east-west-trending, major fault systems that define the plate boundaries in northern Venezuela. 2007 artículo científico 0016-7169 https://www.redalyc.org/articulo.oa?id=56846402 en http://www.redalyc.org/revista.oa?id=568 Geofísica Internacional application/pdf Universidad Nacional Autónoma de México Geofísica Internacional (México) Num.4 Vol.46
format Artículo científico
id redalyc_56846402
institution Redalyc
language en
publishDate 2007
publisher Universidad Nacional Autónoma de México
spellingShingle Source characteristics of the 1989 Boca del Tocuyo earthquakes in northwestern Venezuela
G. Suárez
Ciencias de la Tierra
Venezuela
seismic hazard
Caribbean tectonics
complex seismic rupture
Source characteristics of the 1989 Boca del Tocuyo earthquakes in northwestern Venezuela G. Suárez Gustavo Malavé Ciencias de la Tierra Venezuela seismic hazard Caribbean tectonics complex seismic rupture The Boca del Tocuyo earthquake of April 30, 1989, has a special significance in assessing the seismic hazard of northern Venezuela and in understanding the complex tectonic deformation in this area. Although it was an event of moderate magnitude (Mw=6.2), the mainshock and its largest aftershock (Mw=5.6) produced considerable damage in low-rise structures, mainly due to soil failure, and induced intense liquefaction in most of the coastal towns near the epicentral area. Both earthquakes show body-wave trains which are much longer than those expected for events of such magnitude. The reason for this anomalous duration was analyzed through the formal inversion of the P, SH, and SV waves recorded teleseismically. The results show that the Boca del Tocuyo main event was generated by multiple rupture processes composed of at least two and perhaps three subevents, whereas the aftershock was formed by two subevents. Although the direction of rupture propagation could not be gleaned directly from the teleseismic body wave data, the epicentral relocation of the largest aftershock, the hypocentral distribution of about 60 aftershocks (mb<4.5), and the linearity of the coast, which is parallel to the geologic structures in this area, suggest right-lateral, strike-slip faulting in a NW-SE direction. The Boca del Tocuyo earthquakes were apparently generated on a system of conjugate faults that are oblique to the east-west-trending, major fault systems that define the plate boundaries in northern Venezuela. 2007 artículo científico 0016-7169 https://www.redalyc.org/articulo.oa?id=56846402 en http://www.redalyc.org/revista.oa?id=568 Geofísica Internacional application/pdf Universidad Nacional Autónoma de México Geofísica Internacional (México) Num.4 Vol.46
title Source characteristics of the 1989 Boca del Tocuyo earthquakes in northwestern Venezuela
topic Ciencias de la Tierra
Venezuela
seismic hazard
Caribbean tectonics
complex seismic rupture
url https://www.redalyc.org/articulo.oa?id=56846402