Macauley Island

Macauley Island is a volcanic island in New Zealand's Kermadec Islands, approximately halfway between North Island of New Zealand and Tonga, in the south-west Pacific Ocean. It is part of a larger submarine volcano that features a 10.5-by-7-kilometre (6.5 by 4.3 mi) wide underwater caldera northwest of Macauley Island. Two islets, Haszard Island and Newcome Rock, lie east offshore of Macauley Island. The island is mostly surrounded by high cliffs that make it difficult to access; the inland parts are mostly gently sloping terrain covered with ferns and grasses. The island formed during several volcanic episodes that produced mainly basaltic rocks as lava flows. During the Holocene, a large explosive eruption produced the Sandy Bay Tephra; this eruption may have had a volume of more than 100 cubic kilometres (24 cu mi) and the Macauley caldera might have formed during that occasion. Later, most of the current surface of Macauley Island formed as the Haszard Formation. Two possible eruptions took place during the 19th century offshore Macauley Island; a hydrothermal vent system is active at Macauley Cone in the caldera. Macauley Island is an important breeding place for many seabirds, which come on land only to reproduce. The island is uninhabited but Polynesians and, during the 19th century, whalers introduced goats, pigs and rats which damaged the island's ecosystem. During the 20th and 21st centuries these invasive species were largely eradicated, leading to a recovery of the previous vegetation. The island is part of several protected areas.

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