Tsunamis are traveling waves characterized by large amplitudes and long wavelengths close to the coastline. Often, the first couple of leading waves are either leading-elevation N-waves (LEN waves) or leading-depression N-waves (LDN waves). These waves are usually devastating, causing serious damage to coastal infrastructures or even human casualties. Among various natural disasters related to tsunamis, harbor oscillations are one of the most frequent disasters around the world, which can cause excessive movements of moored ships and rupture mooring lines inside the harbor. In this article, transient harbor oscillations induced by various incident N-waves are first investigated. The transient oscillations are simulated by a fully nonlinear Boussinesq model, FUNWAVE-TVD. The incident N-waves include the TS-type and MS-type isosceles LEN and LDN waves. The TS- and MS-type N-waves correspond to the waveform expressions proposed by Tadepalli and Synolakis  and Madsen and Schäffer , respectively. This paper focuses on the effects of the incident wave amplitude and its type on the relative wave energy distribution inside the harbor. The maximum runup and rundown of various incident waves are also discussed. For comparison, the transient oscillations excited by solitary waves are also considered. The harbor used in this paper is assumed to be long and narrow and has constant depth; the free surface movement inside the harbor is essentially one-dimensional. This study reveals that, for the given harbor, for the range of the incident wave amplitude and the incident wave types studied in this paper, the larger tsunamis lead to a more uniform relative wave energy distribution inside the harbor. The relative wave energy distributions induced by the LDN waves are always more uniform than those induced by the LEN waves, while the relative wave energy distributions induced by the solitary waves are more concentrated than those induced by the various N-waves. When the incident wave amplitude is relatively large, the maximum runups of the LDN waves are considerably larger than those of the solitary waves, while those of the LEN waves are much less than those of the solitary waves.
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Ocean Engineering