Macauley Island

Macauley Island

View from the north-east, 2003
Macauley Island in the Kermadec Islands
Geography
Location	South Pacific Ocean
Coordinates	30°14′S 178°26′W / 30.233°S 178.433°W / -30.233; -178.433
Archipelago	Kermadec Islands
Area	3.06 km2 (1.18 sq mi)
Length	2.5 km (1.55 mi)
Width	1.8 km (1.12 mi)
Highest elevation	238 m (781 ft)
Highest point	Mount Haszard
Administration
New Zealand
Demographics
Population	0
Additional information
Nature Reserve

Macauley Island is a volcanic island in New Zealand's Kermadec Islands, approximately halfway between New Zealand's North Island and Tonga in the southwest Pacific Ocean. It is part of a larger submarine volcano that features a 10.5 by 7 kilometres (6.5 mi × 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 accessing it difficult; the inland parts are mostly gently sloping terrain covered with ferns and grasses.

The island was 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, the Haszard Formation built most of the current surface of Macauley Island. Two uncertain eruptions took place during the 19th century offshore Macauley Island; a hydrothermal vent system is active on Macauley Cone in the caldera.

Macauley Island is an important breeding place for numerous seabirds, which come on land only to reproduce. While the island is uninhabited, Polynesians, and during the 19th century whalers, introduced goats, pigs and rats which damaged the island's ecosystem. During the 20th and 21st century these invasive species were largely eradicated, leading to a recovery of the previous vegetation. The island is part of a protected area.