Site characterization and site response in Port-au-Prince, Haiti

Earthquake Spectra
By: , and 

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Abstract

Waveform analysis of aftershocks of the Mw7.0 Haiti earthquake of 12 January 2010 reveals amplification of ground motions at sites within the Cul de Sac valley in which Port-au-Prince is situated. Relative to ground motions recorded at a hard-rock reference site, peak acceleration values are amplified by a factor of approximately 1.8 at sites on low-lying Mio-Pliocene deposits in central Port-au-Prince and by a factor of approximately 2.5–3 on a steep foothill ridge in the southern Port-au-Prince metropolitan region. The observed amplitude, predominant periods, variability, and polarization of amplification are consistent with predicted topographic amplification by a steep, narrow ridge. A swath of unusually high damage in this region corresponds with the extent of the ridge where high weak-motion amplifications are observed. We use ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) imagery to map local geomorphology, including characterization of both near-surface and of small-scale topographic structures that correspond to zones of inferred amplification.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Site characterization and site response in Port-au-Prince, Haiti
Series title Earthquake Spectra
DOI 10.1193/1.3637947
Volume 27
Issue S1
Year Published 2011
Language English
Publisher Earthquake Engineering Research Institute
Contributing office(s) Earthquake Science Center
Description 19 p.
First page 137
Last page 155
Country Haiti
City Port-au-prince