Jackknifed multiple-window spectra and coherence applied to seismic data

Examines the variance of power spectra and magnitude squared coherences determined from local earthquake seismograms recorded synchronously on a small aperture seismic array. The multiple taper algorithm is used to calculate the spectra and coherences. Variances of these estimates are calculated with the jackknife technique, after transforming to a more normal distribution, and are compared with expected theoretical values. Due to the normalizing process the jackknife 95% confidence limits for the coherences and the spectra are slightly biased compared to theoretical values. The distribution of the jackknife error estimates has a large variance which is most likely caused by the non-stationarity of the original time series.<
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