ABSTRACT
The 25 atolls of the Coral Sea can be divided into three groups. A first group of 15 is associated with an extended region of the eastern Australian continental shelf and are influenced by the South Equatorial Current as it bifurcates near the coastline into the Hiri Current heading north and the East Australian Current heading south. Winds and peak waves are from the east to southeast, and tides that approach 2 m range can generate strong currents. Cyclones can be common. A second group of 8 French Melanesian atolls are found farther to the east on two ridges. The first ridge includes three atolls parallel to the large island of New Caledonia where they lie atop the Loyalty Ridge, a 1,300-km-long zone of uplift associated with the consumption of the Australian plate as it is drawn under the edge of the Pacific plate. Five others are part of the d’Entrecasteaux Ridge, an oceanic arc, that extends from the northern termination of New Caledonia and curves toward the Vanuatu trench. The third group of 2 atolls is between the other two areas and is the Chesterfield Plateau, a high-standing feature of the Coral Sea, the foundation of which is supported by five extinct volcanoes. The plateau consists of two large atoll platforms, Chesterfield and Bellona atolls, that are connected by a saddle. Except for Ouvéa on the Loyalty Ridge, these atolls all form submerged rims.
