A Frequency Domain Approach for Predicting the Signal Strength of Tsunamis at Coastal Tide Gauges

Abstract

ABSTRACT Breaker, L.C.; Murty, T.S., and Carroll, D., 2014. A frequency domain approach for predicting the signal strength of tsunamis at coastal tide gauges. A method for predicting the signal strength of a tsunami at coastal tide gauges once the event is underway is presented. It is based on the calculation of a transfer function for a linear system whose input is obtained from Deep-ocean Assessment and Reporting of Tsunamis (DART) bottom pressure recorders (BPRs) and the output from coastal tide gauges. To perform the calculations, a data window for the input and output signals must initially be chosen that requires a compromise between signal purity and resolution. Limited experience suggests that windows in the range of 6–12 hours duration are a reasonable choice for 1-minute data. The method is illustrated with three examples, the first two taken from the tsunami generated by the Great Tōhoku Earthquake of 2011 and the third from the tsunami generated by the Chilean earthquake of 2010. Magnitude spe...