Inter-model analysis of tsunami-induced coastal currents

Over the last decade, a number of tsunami events originating from distant regions of the Pacific Ocean have impacted the US West Coast. In some cases, the arrival of tsunami waves associated with these events has coincided with low tide levels, such as the 2006 Kuril Islands (Russia) and 2011 Tohoku (Japan) events. This fortunate circumstance helped minimize inundation of dry land, but also illustrated that tsunami-induced water currents can result in severe damage to harbor facilities, moored vessels, and the waterfront infrastructure, in general.

Traditionally, the validation of tsunami numerical models used to predict such events, whether performed by comparison with observations or laboratory experiments, has almost exclusively been centered around the verification of predicted wave elevation values. Recently, the National Tsunami Hazard Mitigation Program addressed the need for the tsunami modeling community to assess how accurately their models predict tsunami currents. To this end, a number of new benchmarking data sets were identified and a workshop was organized in 2015 where tsunami modelers presented results from 13 different models.

The general conclusions of the 2015 workshop are that, while the more sophisticated models tend to correlate better with observations and laboratory experiments, all models presented were able to capture the underlying behavior of the tsunami currents in many areas. Nevertheless, large discrepancies between the models occur in some areas, primarily those associated with regions of strong eddy formation and in the estimation of currents associated with inundating flow. For these regions, the study concluded that the most reliable modeling approach is to combine estimates from different models to generate an average prediction.

Click here to find out more or to read the full article at Ocean Modelling.