Deep-water gravity waves: theoretical estimating of wave parameters

This paper addresses deep-water gravity waves of finite amplitude generated by an initial distur-bance to the water. It is assumed that the horizontal dimensions of the initially disturbed body of the water are much larger than the magnitude of the free surface displacement in the origin of the waves. Initially the free surface has not yet been displaced from its equilibrium position, but the velocity field has already become different from zero. This means that the water at rest initially is set in motion suddenly by an impulse. Duration of formation of the wave origin and the maximum water elevation in the origin are estimated using the arrival times of the waves and the maximum wave-heights at certain locations obtained from gauge records at the locations, and the distances between the centre of the origin and each of the locations. For points situated at a long distance from the wave origin, forecast is made for the travel time and wave height at the points. The forecast is based on the data recorded by the gauges at the locations. 1. Problem outline. In the present study the deep-water waves are considered which start to propagate away from an initially disturbed body of water. Then the water is acted on by no external force other than gravity