Book Description

This study determines the degree of susceptibility of the proposed Barbers Point Deep-draft Pearl Harbor on Oahu Island, Hawaii, to tsunami waves. A finite-difference numerical model was developed to simulate the action of long-period waves within the harbor. This model included the effects of bottom friction, lateral mixing of momentum, radiation losses to the outside ocean, and the flooding of surrounding land areas. A large number of cases were simulated, representing tsunami inputs that could be expected in the area. The resulting water elevations, land flooding, and water movement are presented. The response of the harbor to the many different wave cases was combined with a study of the frequency-of-occurrence statistics for different harbor response events. This was done both for infrequent large tsunamis and for more frequent small amplitude tsunamis. Conservative probability methods were used for all results. On the basis of the response modeling and probability studies, the following conclusions were reached: (a) the harbor does not amplify incident long-period waves, especially those with a period of around 800 sec., (b) this amplification is, however, much smaller than would be predicted by linear response models, such as that of Durham (1978), which neglects nonlinear effects, such as bottom friction, lateral mixing, and flooding, (c) the nature of the harbor response will depend on the character of the incident wave, and (d) the harbor location chosen is a good location for the mitigation of tsunami hazards. (Author).