New Caledonia
The Melanesian island group of New Caledonia is located in the southwest Pacific, astride the Tropic of Capricorn,
lying around 1,200 km off the Queensland coast of eastern Australia. Its main island of Grande Terre — often simply
referred to as New Caledonia by English speakers — is one of the largest islands within the open waters of the Pacific,
with an area of 16,350 km². The territory is an overseas department of France and includes the Loyalty Islands
(Îles Loyauté) to the east.
Located to the northwest are several dependent territories of New Caledonia: the Rêcifs d'Entracasteaux, Bellona Reefs, Chesterfield Reefs and Fairway Reef; to the east are the dependencies of Walpole Island and the small volcanic islands of Hunter and Matthew (both disputed territories with Vanuatu). In all, the territory covers an area of 18,350 km².
The main island of Grande Terre consists of a narrow and lengthy island of 390 km by 50 km orientated northwest to southeast (see panoramic image). The island is composed of a mountainous central spine that runs the entire length of the island, rising to 1,628 m at Mt. Panié in the north. Terrain on the eastern side of the mountains is characterized by steep slopes with that of the west by hilly coasts, lowland plains and wide bays. Off shore, situated on the shallow shelf that surrounds the island and continuing the northwest-southeast trend, are numerous smaller islands including the Île des Pins (152 km²) and Île Ouen (38 km²) in the southeast and southwest respectively, and in the northwest the islands of Yandé, Balabio (33 km²), Baaba and the Îles Belep (67 km²).
The entire island (including the offshore islands mentioned above) are located with in an extensive barrier reef system — the second largest in the world after Australia's Great Barrier Reef. The barrier reefs extend considerable distances to the southeast and northwest, beyond the ends of Grande Terre, forming an extensive lagoon that covers an area of around 24,000 km². The reefs of the northwest are particularly well-developed, extending northwards on either side of the island for 150 km beyond the northwest tip of the island, coming to an end at the Grand Passage that separates them from the Rêcifs d'Entracasteaux. In all, the barrier reefs total 1,300 km in length. The major reef formations include the Récif des Français, Grand Récif de Cook, Grand Récif de Koumac and the Grand Récif du Sud. Within the lagoon that is sheltered by these barrier reefs are found smaller fringing and platform reefs as well as a dozens of small islands and coral cays.
The second largest territorial unit of New Caledonia is that of the Loyalty Islands (Îles Loyauté), covering an area of 1,970 km². Located 110 km to the east of Grande Terre, across a deep ocean basin of 2,000 m in depth, the Loyalty Islands are geologically distinct from the Grande Terre landmass. Being of more recent origins, the islands of the Loyalty group are the flat uplifted remains of former coral reefs and atolls that once formed around a chain of volcanoes. There are three main islands: Lifou (1,196 km²), Maré (650 km²) and Ouvéa (132 km²); as well as the smaller Beautemps-Beaupré Atoll. Between Lifou and Maré are found several smaller islands — including Île Dudun, Île Nié and Île Tiga.
The Loyalty Islands lie upon a submarine feature known as the Loyalty Ridge (or Arc) that extends for around 1,000 km parallel to Grande Terre — the ridge is an example of a long-extinct intra-oceanic volcanic arc. Along this ridge are located a number of features that are included as dependent territories of New Caledonia: the Astrolabe Reefs and Petrie Reef at the northwestern end, and Walpole Island at the southeastern end.
