Distribution of (mb - Ms) of moderate earthquakes along the Mexican seismic zone

We study the spatial distribution of mb-Ms for 55 earthquakes from 1978 to 1994 with focal depth from 0 to 80 km, mb from4.5 to 5.5, which occurred along the Middle America trench, between 95° to 107° W. The mb-Ms values have a bimodal distribution,with peaks at values of 0.3 and 0.8 and minimum at...

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Detalhes bibliográficos
Autor: Vyacheslav M. Zobin
Formato: artículo
Estado:Versión publicada
Fecha de publicación:1999
País:México
Recursos:Universidad de Colima
Repositorio:Redalyc-UCOL
OAI Identifier:oai:redalyc.org:56838105
Acesso em linha:https://www.redalyc.org/articulo.oa?id=56838105
Access Level:acceso abierto
Palavra-chave:Ciencias de la Tierra
Mexico
magnitude
Earthquake
subduction
Descrição
Resumo:We study the spatial distribution of mb-Ms for 55 earthquakes from 1978 to 1994 with focal depth from 0 to 80 km, mb from4.5 to 5.5, which occurred along the Middle America trench, between 95° to 107° W. The mb-Ms values have a bimodal distribution,with peaks at values of 0.3 and 0.8 and minimum at mb-Ms=0.6. Events of the first group, mb-Ms <0.6, were distributed along thetrench over the whole region, and events of the second group, mb-Ms ³ 0.6, were found mainly in the central part of the region,within the Guerrero block. These data show that the Oaxaca block consists of a relatively homogeneous lithosphere, where lowfrequencyevents dominate, while the Guerrero block is more complex radiating both low- and high-frequency events.