NUMERICAL AND PHYSICAL MODELING OF LOCALIZED TSUNAMI-INDUCED CURRENTS IN HARBORS

Abstract

Based on the observations on the recent transoceanic tsunami events, it has been seen that severe damage may still occur in ports and harbors as a result of the strong tsunami-induced currents, even if there is no or limited inundation. Dynamic currents induced by tsunami waves, while regularly observed and known to cause significant damage, are poorly understood. In this paper, it will be discussed that the strongest currents in a port are governed by horizontally sheared and rotational shallow flow with imbedded turbulent coherent structures, and without proper representation of the physics associated with these phenomena; predictive models may provide drag force estimates that are an order of magnitude or more in error. Such an error can mean the difference between an unaffected port and one in which vessels 300 meters in length drift and spin chaotically through billions of dollars of infrastructure. This paper also focuses on tsunami induced currents and seeks to define the relative hazard in specific ports and harbors as a result of these currents.