Exploration of subsoil structure in México city using correlation of micrometremors

We present results of the exploration of the subsoil in the lake bed zone of Mexico City using correlation of microtremors. We recorded microtremors using broad band stations and recording windows between a few minutes and one hour. Vertical components were analyzed using both SPAC and time interfer...

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Detalles Bibliográficos
Autores: Francisco J. Chávez-García, Jorge Aguirre
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2012
País:México
Institución:Universidad Nacional Autónoma de México
Repositorio:Redalyc-UNAM
OAI Identifier:oai:redalyc.org:56823341004
Acceso en línea:https://www.redalyc.org/articulo.oa?id=56823341004
Access Level:acceso abierto
Palabra clave:Ciencias de la Tierra
correlation
Microtremors
subsoil structure
velocity dispersion
lateral heterogeneity
Descripción
Sumario:We present results of the exploration of the subsoil in the lake bed zone of Mexico City using correlation of microtremors. We recorded microtremors using broad band stations and recording windows between a few minutes and one hour. Vertical components were analyzed using both SPAC and time interferometry to recover Rayleigh wave dispersion. Our measurements allow us to compute correlation of microtremors for a very wide range of distances between stations, from 10 m to almost 2 km. At short distances, we obtained significant correlation and the shallow velocity structure could be well determined. We show that lateral heterogeneities of the clay layer are important even over short distances. At larger distances, it was not possible to obtain good correlation. Correlation between two stations requires that the medium, at the wavelength scale of distance between stations, be able to ustain Rayleigh waves. Our results suggest that Rayleigh waves cannot be retrieved from correlation analyses for wavelengths between 1 and 9 km.