The effect of uncertainty in earthquake fault parameters on the maximum wave height from a tsunami propagation model

Abstract

Over the last decade precomputed tsunami propagation model databases have been used extensively for both tsunami forecasting and hazard and risk assessment. However, the effect of uncertainty in the earthquake source parameters on the results of the simulated scenarios of tsunami propagation has not always been examined in great detail. Here we have undertaken a systematic study of the uncertainty in the maximum wave height of a tsunami (hmax) as a function of the uncertainty in the rupture parameters of the earthquake that generates it (specifically the strike, dip, rake, depth and magnitude). We have shown that even for the simple case of a tsunami propagating over flat bathymetry, the coefficient of variation (CoV) and skewness of the distribution of hmax was a complex function of the choice of rupture parameter, distance and azimuth. The relationships between these parameters and CoV became even more complex as the bathymetry used became more realistic. This has major potential implications for both how warning centres operate in the future and how the uncertainty in parameters describing the source should be incorporated into future probabilistic tsunami hazard assessments.