Exploration of subsoil structure in Mexico city using correlation of micrometremors
We present results of the exploration of the subsoil in the la ke 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 interfe...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2012 |
| País: | México |
| Institución: | UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO |
| Repositorio: | Geofísica Internacional |
| Idioma: | español inglés |
| OAI Identifier: | oai:revistagi.geofisica.unam.mx:article/430 |
| Acceso en línea: | http://revistagi.geofisica.unam.mx/index.php/RGI/article/view/430 |
| Access Level: | acceso abierto |
| Palabra clave: | microtremores correlación dispersión de velocidad estructura del subsuelo heterogeneidad lateral microtremors correlation velocity dispersion subsoil structure lateral heterogeneity |
| Sumario: | We present results of the exploration of the subsoil in the la ke 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 sustain Rayleigh waves. Our results suggest that Rayleigh waves cannot be retrieved from correlation analyses for wavelengths between 1 and 9 km. |
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