Effect of a submerged reef chain on periods of sea-level oscillations in Western Australia

Abstract

A seiching type of sea-level oscillation recorded in Western Australia by Allison and Grassia (1979) is influenced by a submerged reef chain parallel to the shore. Being submerged, the reef chain forms an obstruction, causing the water between it and the shore to be partly open to the ocean. The effect of such a partial obstruction is studied in this paper, both theoretically and experimentally. Results indicate that even a comparatively small gap above the reef chain gives rise to periods of oscillations close to that of a fully open basin. On the other hand, presence of a comparatively smalI reef gives rise to seiching with periods nearly of the fully open basin, even in the case of the absence of a significant step to deep water in the bottom topography beyond the reef chain.