ABSTRACT
The eight atolls of the North West Australia Shelf are divided into three groups, all rising from waters several hundred meters deep and develop submerged rims. The southerly group includes Imperieuse, Clerke, and Mermaid reefs, each similar in size and shape, that rise from increasing depths to the northeast and exhibit greater lagoon infill from north to the south. Scott and Seringapatam constitute a second group of two atolls, features that rise from 400 to 700 m from a terrace on the continental slope. Three additional atolls, Cartier, Ashmore, and Hibernia, lie on shelf close to the Timor Sea, where the Australian continental shelf connects with that of New Guinea. The area is generally shallow and tidally dominated, the result of spring tides with 4 m range that can move bottom sediment at depths of 100 m. The primary surface currents in the area originate in the western Pacific and emerge through the several passages into the Indian Ocean shelf as part of a complex exchange through the Timor Sea called the Indonesian Throughflow. This flow, along with the Holloway Current flowing near the outer shelf, affects the Australian outer shelf reefs.
