Strong Ground Motion from the Michoacan, Mexico, Earthquake

Abstract

The network of strong motion accelerographs in Mexico includes instruments that were installed, under an international cooperative research program, in sites selected for the high potenial of a large earthquake. The 19 September 1985 earthquake (magnitude 8.1) occurred in a seismic gap where an earthquake was expected. As a result, there is an excellent descripton of the ground motions that caused the disaster.

FINSIM--a FORTRAN Program for Simulating Stochastic Acceleration Time Histories from Finite Faults

“…As an example of FINSIM's performance, we show results of the simulation of ground motions at the Caleta de Campos station for the M 8.1 1985 Michoacan, Mexico earthquake (Anderson et al, 1986). At a distance of approximately 14 km, this was the closest station to the fault rupture, which had an area of approximately 150 • I40 km (Somerville et al, 1991).…”

Seismic responses of a hemispherical alluvial valley to SV waves: a three-dimensional analytical approximation

“…It has been observed that the sediment conditions of a local site have significant effects upon amplification of ground motions during earthquakes. One of the examples is the Michoacon, Mexico, earthquake in 1985 [1]. As reported in [1], two strong shocks caused a middle level destruction in the areas near the epicenter, but more severe damages in the Mexico City, which is far from the epicenter and located on a thick bathtub soft clay stratification.…”

“…One of the examples is the Michoacon, Mexico, earthquake in 1985 [1]. As reported in [1], two strong shocks caused a middle level destruction in the areas near the epicenter, but more severe damages in the Mexico City, which is far from the epicenter and located on a thick bathtub soft clay stratification. It was reported that the earthquake-induced ground motion of basin is magnified six times or even more, and the aggregation and magnification of seismic waves in the basin is the main reason for the serious damages.…”

NEHRP Site Classification and Preliminary Soil Amplification Maps of Lamphun City, Northern Thailand

“…Table 1 shows the site soil profile classification system used by NEHRP. In (year of study of [13]) [13] evaluated the use of the average SWV in the upper 30 m. According to their work, attenuation affects ground motions as much as the SWV, particularly for deeper geologic deposits. Although attenuation is not directly included in the current NEHRP provisions, it is accounted for in seismic hazard maps.…”