Effects of shallow-layer reverberation on measurement of teleseismic P wave travel times for ocean bottom seismograph data

We conducted synthetic experiments to evaluate the effects of shallow-layer reverberation in oceanic regions on P-wave travel times measured by waveform cross-correlation. Time shift due to waveform distortion by the reverberation was estimated as a function of period. Reverberations in the crystalline crust advance the P waves by a frequency-independent time shift of about 0.3 sec in oceans. Sediment does not affect the time shifts in the mid ocean regions, but effects as large as -0.8 sec or more occur where sediment thickness is greater than 600 m for periods longer than 15 sec. The water layer causes time delays (+0.3 sec) in the relatively shallow (