CONTINENTAL-SHELF RESPONSE TO FORCING BY DEEP-SEA INTERNAL WAVES

A two-dimensional, linear, hydrostatic model is used to investigate the response over a continental shelf as a result of forcing by deep-sea internal waves with nearly arbitrary form. A flat-bottomed deep sea is assumed to have an upper layer with uniform density which extends deeper than the shelf-break depth. The stratification below this layer is continuous and arbitrary. For this stratification, it is shown that the influence of the deep sea can be entirely represented by a simple boundary condition for the shelf flow imposed at the shelf-break. Solutions over the shelf are obtained for particular cross-shelf depth profiles and consist of an image of the incident wave form which propagates back and forth across the shelf, being perfectly reflected at the coast but only partially reflected at the shelf-break. The amplitude of the shelf response generally increases with stronger stratification and/or a shallower shelf-break and can be large for some oceanic conditions. Shoaling topography leads to an amplified sea-level response near the coast and may produce an irregular pattern of oscillations.