Campbell Plateau
The Campbell Plateau is a large underwater plateau located south of New Zealand and the Chatham Rise. It is part of Zealandia, a mostly submerged continent, and began to form when the supercontinent Gondwana broke apart about 80 million years ago. The above‑sea‑level parts of the plateau include the Bounty Islands, Antipodes Islands, Auckland Islands, and Campbell Island, which are together known as the New Zealand Subantarctic Islands and were made a World Heritage Site in 1998.
The plateau covers about 800,000 square kilometers. Much of its seabed sits deep, with depths under 1,000 meters, but it rises to about 500 meters at the Pukaki Rise and some areas, like the Auckland and Campbell Islands, emerge above the sea. Its landscape is a gently rolling plain with major rises running roughly east–west, such as the Campbell Island Rise, Pukaki Rise, and Bounty Island Ridge. On the western edge there are two near‑parallel rises (Stewart Island–Snare Island Rise and the Auckland Island platform). The continental slopes are steep on the western and southern sides, while the northern edge slopes down into the Bounty Trough.
Geologically, the Campbell Plateau is a triangular, cratonic microcontinent made from continental crust, formed during the Gondwana breakup. Much of the land is granitic rock from the Paleozoic era, overlain by younger volcanic rocks on the Auckland and Campbell Islands. The crust here is unusually thin, and scientists debate the reason—likely either an Early Cretaceous extension or the Late Cretaceous separation of New Zealand from Antarctica. The same breakup created the Great South Basin, where about 8 kilometers of sediments have accumulated, and the Bounty Trough.
The western islands (Auckland, Snares, and Stewart) have Middle Cretaceous granite basement rocks around 100–120 million years old, with metamorphism ending around that time on Snares and Stewart. Campbell Island and Fiordland have Paleozoic schists as their basement. The Bounty Islands are made of older granodiorite rocks, with some Precambrian–Cambrian material nearby. The Antipodes Islands are built mainly from Quaternary alkaline basalts. Many plate‑tectonic models place the Campbell Plateau with nearby large crustal blocks (Lord Howe Rise, Challenger Plateau, and the Ross Sea) before Gondwana broke up, sharing a history of crustal thinning and underplating in the Early Cretaceous or Jurassic.
There are two magnetic anomaly systems in the area, SMAS and CMAS, whose origins are still debated. The islands are important breeding grounds for many species, including royal albatross, crested penguin, and Hooker’s sea lion. Biologically and geologically, parts of southern South Island are linked to the Campbell Plateau, and the area hosts several endemic species.
Macquarie Island is biologically connected to the Campbell Plateau, though it sits on oceanic crust formed at the Macquarie triple junction, which has moved over time due to seafloor spreading. The two areas share several unique species and ecological ties.
South of the Campbell Plateau lies the Antarctic Circumpolar Current (ACC), which flows around the Macquarie Ridge and along the plateau’s eastern edge before turning eastward again at about 50–55 degrees south. A wind‑driven surface current (Ekman transport) also moves water across the plateau, influencing how Subantarctic and subtropical waters mix as they travel toward the Chatham Rise north of the plateau.
This page was last edited on 2 February 2026, at 15:34 (CET).