Norfolk Island's geography: a cliff-bound summit of a sunken ridge

Where the island sits in the Pacific

The territory lies in the South Pacific between New Zealand and New Caledonia, about 1,412 kilometres east of Evans Head on the New South Wales coast and about 900 kilometres from Lord Howe Island. Britannica gives the distance from Sydney as 1,676 kilometres. The main island sits at 29 degrees south. It is about 8 kilometres long and 5 wide, and its coastline runs for about 32 kilometres.

Three islands make up the territory: Norfolk Island itself, Phillip Island about six kilometres to the south, and the small Nepean Island close inshore off Kingston. There are no neighbours by land and none within sight. The nearest weather station the Bureau of Meteorology can list to Norfolk Island Aero lies more than 300 kilometres away.

Around the islands, Australia claims an exclusive economic zone of 200 nautical miles, roughly 428,000 square kilometres of sea. Part of it forms the Norfolk Marine Park, which covers 188,444 square kilometres with depths from the high tide mark to 5,000 metres.

How volcanoes built a ridge top

Norfolk and Phillip islands are what is left of several basalt eruptions between 3.1 and 2.3 million years ago. Geologists recognise four main layers of lava, the oldest called the Ball Bay basalts and the youngest the Steeles Point basalts, and much of the volcanic pile has since been worn away. The flows lie horizontally, and in most places they are covered by red lateritic soil, fertile but easily washed off once the plants holding it are cleared.

The islands are the highest points of the Norfolk Ridge, a long, narrow, steep-sided ridge on the sea floor with seamounts and pinnacles along it. The ridge is part of Zealandia, a mostly submerged continental mass, and it carries deep-water species between New Zealand and New Caledonia. Both of those countries have protected areas adjoining the Norfolk Marine Park along the ridge.

Nepean Island is different rock: a late Pleistocene limestone of sand and broken coral and shell cemented together, a stone also found in a small patch of Norfolk Island near Kingston. Phillip Island is a volcanic pinnacle rising to about 275 metres.

Where the high ground is

The island's mean height above the sea is about 110 metres, according to Britannica. Mount Bates, in the north-west quadrant, reaches 319 metres, and its neighbour Mount Pitt 318. Most of the rest of the surface is rolling ground suitable for grazing and farming. The island is classed as its own subregion, PSI02, of the Pacific Subtropical Islands region in Australia's biogeographic scheme, covering 3,908 hectares.

Why the cliffs shape everything on land

The coast is cliff almost the whole way round, some of it more than 90 metres high. Kingston on the south coast and the landing place at Cascade on the north are among the few points where it is not. Ground slopes gently to the sea at Slaughter Bay and Emily Bay, which is why the first settlement in 1788 was built at Kingston.

There is no harbour. Jetties at Kingston and Cascade let small boats land cargo, but ships cannot come close to either. A supply ship anchors off, and whaleboats towed by launches bring its freight in five tonnes at a time to whichever jetty lies on the sheltered side that day. Everything the island does not produce arrives this way, usually through Cascade Bay. Emily Bay, protected from the open Pacific by a small coral reef, is the only place considered safe for ordinary swimming. Anson Bay and Ball Bay on the exposed coasts are known for surf.

The reef lagoon at Emily and Slaughter Bay has suffered from storm water and groundwater running off the land. Since 15 February 2023 the whole lagoon has been a no-take area, and Cemetery Bay next to it is closed to the taking of sea cucumbers, urchins, starfish and their relatives, which with the plant-eating fish help keep algae in check. Fishing for kingfish and other finfish is still allowed at Cemetery Bay.

How the sea around the island is managed

The marine park is divided into National Park and Multiple Use zones offshore and a Special Purpose Zone immediately around the island, which allows both conservation and local use. More than 20 known shipwrecks inside it are protected under the Historic Shipwrecks Act, among them HMS Sirius, lost in 1790. Whales were hunted from the island until 1956. Humpback, minke and sei whales and dolphins are still seen close to shore, and humpbacks pass on their migration.

What the climate is like through the year

The Bureau of Meteorology's station at Norfolk Island Aero, 112 metres above the sea near the airport, has kept rainfall records since 1890 and temperatures since 1939. The climate is subtropical and mild, classed as humid subtropical (Cfa), with little difference between the seasons. Summer days average about 25 degrees and winter days about 18.

Rain falls in every month, but more in winter, from April to August. Over 132 years of record to 2026 the annual mean has been 1,280.5 millimetres, with June the wettest month at 142.6 millimetres and November the driest at 73.3. Rain of a millimetre or more falls on about 120 days a year on average, and the island gets about 6.8 hours of sunshine a day across the year.

Cloud is common. Over the years the station measured it, from 1939 to 2010, it recorded about 148 cloudy days a year against 41 clear ones, with the clearest skies in August and September. The air is humid, at 76% relative humidity on an average morning, and the wind is steady: the mean afternoon wind speed is 18.2 kilometres an hour, with little change from month to month.

The extremes are narrow too. The highest temperature on record, 28.5 degrees, was measured on 23 January 2024, and the lowest, 6.2 degrees, on 29 July 1953.

What the forest was and what replaced it

Before 1788 subtropical rainforest covered almost all of Norfolk Island. Norfolk Island pines formed the canopy in exposed places, and the Norfolk Island palm and tree ferns grew in the sheltered gullies, with a thick understorey of vines and ferns. The pine can grow to 60 metres. It is the tree on the territory's flag and is grown as an ornamental tree around the world.

Two centuries of clearing changed the cover. Both convict settlements cleared land for crops. The Pitcairn families farmed their land grants, and attempts around 1900 to export lemons, passionfruit and bananas, together with forestry plantations and cattle pasture, took more of the forest. Parks Australia describes the result as a pastoral country of rolling green hills in place of the original rainforest. About a quarter of the island is permanent pasture, and there is no irrigated land.

What the national park protects

Norfolk Island National Park was first declared on 31 January 1986 around Mount Bates and Mount Pitt, and its Phillip Island section was proclaimed on 24 January 1996. The park and the botanic garden now hold most of the island's remaining natural areas, and the park covers about a tenth of the main island's land.

Parks Australia counts about 200 native plants in the island group, 46 of them found nowhere else and 15 currently rated critically endangered. Other counts differ: one tally gives 174 native species and 51 endemics. The Norfolk Island palm and the smooth tree-fern are common inside the park and rare outside it. Weeds are the main pressure, and one survey found more weed species on the island than native ones. Cherry guava, known locally as porpei, has taken over large parts of the park, and because biosecurity rules forbid bringing plants in, rangers grow every replacement native from seed collected on the island. Some critically endangered endemics, among them the broadleaf meryta, now grow in numbers along the park's walking trails.

How the island's animals arrived and which survived

An island never joined to a continent was colonised only by animals that could fly, swim or drift there. Norfolk has no endemic mammals, and its only native mammals, two kinds of bat, are now extinct on the island. Two small reptiles, a gecko and a skink, survive on Phillip Island, where rats and cats never established themselves; fossils show they once lived on the main island too.

Birds fared unevenly. Parks Australia records about 116 bird species. The Norfolk kākā, the Norfolk pigeon and the Norfolk ground dove are extinct, along with island forms of the thrush, the starling and the triller. The Norfolk Island morepork owl was down to a single female, known as Miamiti, in the mid-1980s; two male New Zealand moreporks were brought in, and a hybrid population is recovering. The green parrot, also endangered, has grown with rodent control and nest protection to an estimated 300 to 350 birds. Land snails radiated into about 40 endemic species on the island, and rats and feral fowl have hit them hard: five species are critically endangered.

Which seabirds nest on the outer islands

The smaller islands carry most of the seabirds. White-necked and Kermadec petrels, wedge-tailed shearwaters, Australasian gannets, red-tailed tropicbirds and grey ternlets breed there, and the providence petrel, hunted to local extinction by the early 19th century, has shown signs of returning to Phillip Island. The sooty tern, called the whale bird on the island, has long had its eggs collected in season by islanders. BirdLife International lists Norfolk and Nepean islands as an Important Bird Area for the whole populations of several endemic land birds, and treats Phillip Island as a separate one.

How Phillip Island came back

Pigs and rabbits brought in during the convict era stripped Phillip Island almost bare, leaving it red-brown when seen from Norfolk. Rabbits were eradicated in 1986, and the vegetation has been recovering since. The island is now on the Commonwealth Heritage List as a nesting place for masked boobies, black-winged petrels, sooty terns and black noddies, and as habitat for plants and animals once thought extinct on the main island.

Where people live on the land

The island has no cities, only towns and hamlets. Burnt Pine, strung along Taylors Road in the centre of the island near the airport, holds the shops, the post office and the community hall. Kingston, on the flat ground behind the south-coast landing, holds the courts and government buildings in the old convict settlement and is the territory's capital. Government House, the Administrator's residence, stands on Quality Row there. Kingston's role is largely ceremonial; most of the island's commerce happens in Burnt Pine. Elsewhere settlement is widely separated homesteads spread over much of the island, at places such as Cascade, Middlegate, Longridge, Anson Bay and Steeles Point. How the island earns its living from this land and sea is covered in the economy of Norfolk Island.