Modelling on the Continental Shelf
Oceans have a general structure which is dictated by their geographical origin. There are mid-oceanic ridges, trenches and, most important for us here, continental shelves. These shelves border the margins of the oceans, the seas over them are only about 200 m deep, and the transition from this 200 m to the oceanic 3000–4000m is achieved through a relatively small region, the continental slope — which is aptly named, since the slope is commonly quite mild, only 4°. Simple trigonometry shows that the depth can sink from 200 m to 3000 m in a horizontal distance of 40 km with the slope. Since the width of the ocean is measured in thousands of kilometres, and most continental shelves are hundreds of kilometres wide, this slope region is of insignificant horizontal extent. It is of course, only the dimension that is insignificant. The continental slope contains important currents and is a significant source and sink of energy for many different types of flow. However, importantly for continental shelf modellers it serves to mark the border between deep ocean and continental shelf, and is the site of the open boundary condition. The dimensions of the continental shelf render models of continental shelf seas quite distinct from ocean models. In this chapter we shall be looking at modelling the waves and currents that occur on the world’s continental shelves and also the waves that exist and may be trapped on the continental slope. Let us start with surface water waves.
KeywordsContinental Shelf Storm Surge Continental Slope Water Wave Tidal Model
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