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INSTRUMENT CORRECTION AND DYNAMIC SITE PROFILE VALIDATION AT THE CENTRAL UNITED STATES SEISMIC OBSERVATORY, NEW MADRID SEISMIC ZONEBrengman, Clayton M.J. 01 January 2014 (has links)
The Central United States Seismic Observatory (CUSSO), is a fifteen-element array of three-component accelerometers and seismometers in the New Madrid seismic zone, within the upper Mississippi embayment. Its location within the thick (up to 1 km) sequences of unlithified sediment comprising the embayment, make CUSSO a unique array in its ability to directly measure seismic wave propagation, including ground motion site effect; however, before the observational data can be used for analysis, the orientation and instrument response of the CUSSO array must be defined. This study used cross-correlation and direct comparisons to filter out the instrument response and determine the instrument orientation, making CUSSO data ready for analysis, and making CUSSO a viable calibration site for other free-field sensors in the area. The corrected waveforms from five far-field earthquakes with magnitudes ranging between 2.5 and 4.7, which were recorded at CUSSO, were used to validate the site’s proposed dynamic soil model. The corrected bedrock motions were also numerically propagated through the CUSSO soil profile (transfer function) and compared, in terms of both peak acceleration and amplitude spectra, to the recorded surface observations.
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