A comparison of the spectral characteristics of observed and simulated tsunamis

Abstract

The spectra of real tsunamis depend on the source characteristics, propagation effects on the deep ocean, shelf topography and harbour geometry. The separation between all these effects is possible if a large number of instrumental tsunami data is available and, in that case, the source parameters may be computed by cancellation of path and instrumental effects. This is not generally the case in the SW Iberian region, where, in spite of some very large historical events there is only a small number of instrumental tsunamis. A good case study for that methodology is given by the 28.02.1969 tsunami, which has been previously studied with rather encouraging results in terms of the comparison of arrival times and amplitudes between observed and simulated tsunamis. The aim of the present study is the comparison between the spectral characteristics of instrumental tide records and the synthetic wave forms computed with a shallow water model.