Finite-Fault Modeling of Strong Ground Motions for the 1995, Mw 8, Colima-Jalisco, Mexico, Earthquake
Abstract
The 9 October 1995 Colima-Jalisco subduction earthquake (Ms 7.4, Mw 8.0) occurred in the Middle American Trench, about 35 km southwest of Manzanillo, Mexico, producing considerable damage for buildings located near the epicentral area. Notable damage was also reported in the city of Guadalajara with an epicentral distance of about 240 km due to local site effects (Chavez, 1998). Here, three-component strong ground motion records were obtained for the mainshock as well as for the 6 October foreshock and 12 October aftershock at a station equipped with an SSA-2 (soil, 9 m depth) and two FDH23 Kinemetrics (rock, 35 m depth) accelerographs in the free field. In this study we present broadband synthetics for the strong motion records of the mainshock using a hybrid method combining long-period and high-frequency simulations. The long-period (< 1 Hz) wavefield was simulated using a 4th-order finite-difference method including a finite-fault description of the source with 4 asperities in a 2.5D model constrained by gravity data. The high-frequency (> 1 Hz) synthetics were generated with empirical Green functions including recordings of the fore- and aftershocks. Compared to the strong motion data our synthetics show a good fit for both the long-period waveforms and high-frequency spectra.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2001
- Bibcode:
- 2001AGUFM.S42C0663C
- Keywords:
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- 7212 Earthquake ground motions and engineering