Earthquake ground motion in Mexico City: An analysis of data recorded at Roma array
✍ Scribed by Martín Cárdenas-Soto; Francisco J. Chávez-García
- Book ID
- 104093406
- Publisher
- Elsevier Science
- Year
- 2007
- Tongue
- English
- Weight
- 839 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0267-7261
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✦ Synopsis
We analysed in detail three earthquakes recorded in a small-aperture accelerometric array in Mexico City, using the correlation of the records as a function of time along the accelerogram and frequency. Ground response is strongly conditioned by the fundamental period of the soft soils at the site of the array (T 0 ). Energy at periods longer than 2T 0 is guided by the crustal structure (with a thickness of 45 km). The wave field at periods between T 0 and 2T 0 also consists of surface waves but guided by the upper 2-3 km of volcanic sediments in central Mexico. For periods smaller than T 0 , ground motion is uncorrelated among the stations. Our results indicate that seismic response of Mexico City, including its very long duration, results from deeply guided surface waves (between 2 and 45 km depth) interacting with the very local response of the soft surficial clay layer.