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 Portau- 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 smallscale topographic structures that correspond to zones of inferred amplification. © 2011, Earthquake Engineering Research Institute.
CITATION STYLE
Hough, S. E., Yong, A., Altidor, J. R., Anglade, D., Given, D., & Mildor, S. L. (2011). Site characterization and site response in port-au-prince, Haiti. Earthquake Spectra, 27(SUPPL. 1). https://doi.org/10.1193/1.3637947
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