NEHRP Clearinghouse

Title
Bedrock Accelerations in Memphis Area Due to Large New Madrid Earthquakes.
File
PB90162330.pdf
Author(s)
Hwang, H. H. M.; Chen, C. H.; Yu, G.
Source
National Center for Earthquake Engineering Research, Buffalo, NY.; National Science Foundation, Washington, DC., November 7, 1989, 68 p.
Abstract
Memphis and Shelby County are geographically close to the southern segment of the New Madrid seismic zone (NMSZ). The NMSZ is being regarded by seismologists and earthquake engineers as the most hazardous zone in the eastern United States. In the study, a seismologically-based model is used to describe the horizontal bedrock motions at a site due to primarily shear waves generated from a seismic source. The model is centered on a power spectrum which is in turn developed from a seismologically-based Fourier amplitude spectrum. From the power spectrum, earthquake time histories and probability-based response spectra can be generated directly. The power spectrum generated in the study can also be used to estimate the peak value of earthquake acceleration based on the extreme value distribution of a random process. The peak values of horizontal bedrock accelerations for Memphis and Shelby County are computed for two New Madrid earthquakes of M = 7.5 and 6.5. Two different cases of seismic sources are considered: (1) a single source at Marked Tree, Arkansas, and (2) the southern segment of the NMSZ. The results are presented in contour maps.
Keywords
New Madrid Seismic Zone; Acceleration (Physics); Ground motion; Bedrock; Earthquake engineering; Earthquakes; Random processes; New Madrid earthquakes; Seismic effects; Memphis (Tennessee); Shelby County (Tennessee); Power spectra; Seismic risk