A method for determining tsunami hazard is presented using simple seismological and hydrodynamic models. 

The seismological model assumes that submarine earthquakes of the dipstrike type can occur, with equal likelihood, anywhere along a well-defined straight fault and that the site under consideration lies on the perpendicular bisector of and far removed from the fault. The ground dislocation is circular in the horizontal plane, and the vertical offset is uniform. The radius of the circle and the vertical offset are related to seismic moment which is assumed to be random. 

The hydrodynamic model is based on linear dispersive wave theory. It is assumed that the earth is flat, water depth constant, and ocean infinite in horizontal extent. The maximum elevation of water surface of the leading wave is related to ground motion characteristics (or seismic moment) and the distance from the site to the source. 

The probability of the event that the water elevation at a site exceeds an arbitrary but specified level is then derived and computed. A sensitivity study is performed to determine the importance of various parameters.

A preliminary investigation of tsunami hazard

Rapid onset natural hazards have claimed more than 2.8 million lives worldwide in the past 20 years. This category includes such events as earthquakes, landslides, hurricanes, tornados, floods, volcanic eruptions, wildfires, and tsunamis. Effective hazard mitigation is particularly difficult in such cases, since the time available to issue warnings can be very short or even nonexistent. This paper presents the concept of a local warning system that exploits and integrates the existing technologies of risk evaluation, environmental measurement, and telecommunications. We describe Project THRUST, a successful implementation of this general, systematic approach to tsunamis. The general approach includes pre-event emergency planning, real-time hazard assessment, and rapid warning via satellite communication links.

On mitigating rapid onset natural disasters: Project THRUST (Tsunami Hazards Reduction Utilizing Systems Technology)

Tsunami hazard along the U.S. Atlantic coast

Protection from potential tsunami effects is a design criterion for coastal nuclear power plants, especially on the U.S. Pacific Coast and in Puerto Rico. Because of the uncertainties involved in the probabilistic approach, the U.S. Nuclear Regulatory Commission uses a deterministic approach to conservatively estimate tsunami runup, drawdown, and the resulting effects at proposed nuclear power plant sites. However, because of the lack of good data to verify the tsunami models used, very conservative input parameters are used in tsunami analysis. The results may lead to overly conservative and expensive designs for the protection of nuclear power plants from the effects of tsunamis. We, therefore, call for tsunami research in specific areas in order to obtain more realistic estimates of tsunami effects in the future.

Tsunami protection of coastal nuclear power plants in the United States

Coastal power plant siting and safety analysis requires consideration of wave action and extreme water levels, both high and low. The run-up of large amplitude long waves, such as tsunamis, may pose a hazard to a coastal facility through direct dynamic effects on plant structures, through destruction of protective breakwaters and beaches, and the like. Extreme low water levels are of concern in design of coolant intake structures. The importance of tsunamis in these analyses, especially long Pacific coasts, makes specification of potential tsunami histories necessary. The present report addresses this problem. A large hypothetical earthquake is defined by appeal to history and tectonic theory. This canonical source serves as input to a numerical hydrodynamic model which computes the resulting wave history anywhere within the ocean basin. This procedure is repeated for a number of potential source locations, chosen according to degree and type of seismic activity. In this way, hypothetical coastal histories of great tsunamis emanating from any potential source area are simulated. The results of this study are offshore incident wave systems and do not include the complex, site-dependent, nearshore transformation. Users must account for such local effects in any specific application.

D. Divoky

Papers

Tsunami atlas for the coasts of the United States