New Guinea - Geography

Geography

New Guinea is an island in the north of the continent of Sahul, also known as Greater Australia. It is isolated by the Arafura Sea to the west and the Torres Strait and Coral Sea to the east. Sometimes considered to be the easternmost island of the Malay archipelago, it lies north of Australia's Top End, Gulf of Carpentaria and Cape York peninsula, and west of the Bismarck Archipelago and the Solomon Islands Archipelago.

The shape of New Guinea is often compared to that of a bird of paradise, and this results in the usual names for the two extremes of the island: the Bird's Head Peninsula in the northwest (Vogelkop in Dutch, Kepala Burung in Indonesian; also known as the Doberai Peninsula), and the Bird's Tail Peninsula in the southeast (also known as the Papuan Peninsula).

A spine of east–west mountains, the New Guinea Highlands, dominates the geography of New Guinea, stretching over 1,600 km (1,000 mi) from the 'head' to the 'tail' of the island. The western half of the island of New Guinea contains the highest mountains in Oceania, rising up to 4,884 m (16,024 ft) high, and ensuring a steady supply of rain from the equatorial atmosphere. The tree line is around 4,000 m (13,100 ft) elevation and the tallest peaks contain permanent equatorial glaciers—which have been retreating since at least 1936. Various other smaller mountain ranges occur both north and west of the central ranges. Except in high elevations, most areas possess a warm humid climate throughout the year, with some seasonal variation associated with the northeast monsoon season.

The highest peaks on the island of New Guinea are:

• Puncak Jaya, sometimes known by its former Dutch name Carstensz Pyramid, is a mist covered limestone mountain peak on the Indonesian side of the border. At 4,884 metres (16,024 ft), Puncak Jaya makes New Guinea the world's fourth highest landmass.
• Puncak Mandala, located in Papua, is the second highest peak on the island at 4,760 metres (15,617 ft).
• Puncak Trikora, also in Papua, is 4,750 metres (15,584 ft).
• Mount Wilhelm is the highest peak on the PNG side of the border at 4,509 metres (14,793 ft). Its granite peak is the highest point of the Bismarck Range.
• Mount Giluwe 4,368 metres (14,331 ft) is the second highest summit in PNG. It is also the highest volcanic peak in Oceania.

Another major habitat feature is the vast southern and northern lowlands. Stretching for hundreds of kilometres, these include lowland rainforests, extensive wetlands, savanna grasslands, and some of the largest expanses of mangrove forest in the world. The southern lowlands are the site of Lorentz National Park, also a UNESCO World Heritage Site. The northern lowlands are drained principally by the Mamberamo River and its tributaries on the Indonesian side, and by the Sepik on the PNG side; the more extensive southern lowlands by a larger number of rivers, principally the Digul on the Indonesian side and the Fly on the PNG side. These are the island's major river systems, draining roughly northwest, northeast, southwest, and southeast, respectively. Many have broad areas of meander and result in large areas of lakes and freshwater swamps. The largest island offshore, Dolak (Frederik Hendrik, Yos Sudarso), lies near the Digul estuary, separated by a straight so narrow it has been named a "creek".

New Guinea contains many of the world’s ecosystem types: glacial, alpine tundra, savanna, montane and lowland rainforest, mangroves, wetlands, lake and river ecosystems, seagrasses, and some of the richest coral reefs on the planet.

Prior to the 1970s, archaeologists called the single Pleistocene landmass by the name Australasia, although this word is most often used for a wider region that includes lands like New Zealand that are not on the same continental shelf. In the early 1970s they introduced the term Greater Australia for the Pleistocene continent. Then at a 1975 conference and consequent publication, they extended the name Sahul from its previous use for just the Sahul Shelf to cover the continent.