Australia, Land and Resources
Australia lacks mountains of great height; it is one of the world’s flattest landmasses. The average elevation is about 300 m (about 1,000 ft). The interior, referred to as the outback, is predominantly a series of great plains, or low plateaus, which are generally higher in the northeast. Low-lying coastal plains, averaging about 65 km (about 40 mi) in width, fringe the continent. In the east, southeast, and southwest, these plains are the most densely populated areas of Australia.
In the east the coastal plains are separated from the vast interior plains by the Great Dividing Range, or Eastern Highlands. This mountainous region averages about 1,200 m (about 4,000 ft) in height and stretches along the eastern coast from Cape York in the north to Victoria in the southeast. Much of the region consists of high plateaus broken by gorges and canyons. Subdivisions of the range bear many local names, including, from north to south, the New England Plateau, Blue Mountains, and Australian Alps; in Victoria, where the range extends westward, it is known as the Grampian Mountains, or by its Aboriginal name, Gariwerd. The highest peak in the Australian Alps, and the highest in Australia, is Mount Kosciusko (2,228 m/7,310 ft), in New South Wales.
A section of the Great Dividing Range is in Tasmania, which is located about 240 km (about 150 mi) from the southeastern tip of the continent and is separated from it by Bass Strait. The waters of the strait are shallow, with an average depth of 70 m (230 ft). The major islands in the strait are the Furneaux Group and Kent Group in the east, and King, Hunter, Three Hummock, and Robbins islands in the west.
The western half of the continent is an enormous plateau, about 300 to 450 m (about 1,000 to 1,500 ft) above sea level. The Great Western Plateau includes the Great Sandy, Great Victoria, and Gibson deserts. Western Australia has, in its northern half, several isolated mountain ranges, including the King Leopold and Hamersley ranges. The interior is relatively flat except for several eroded mountain chains, such as the Stuart Range and the Musgrave Ranges in the northern part of South Australia and the Macdonnell Ranges in the southern part of the Northern Territory.
The central basin, or the Central-Eastern Lowlands, is an area of vast, rolling plains that extends west from the Great Dividing Range to the Great Western Plateau. In this region lies the richest pastoral and agricultural land in Australia. Uluru (Ayers Rock), in the center of Australia in Uluru-Kata Tjuta National Park, is one of the largest monoliths in the world. It is 9 km (6 mi) around its base and rises sharply to some 348 m (1,142 ft) above the surrounding flat, arid land. Other mountain ranges of limited size in the central part of Australia are the Flinders Ranges and Mount Lofty Ranges in South Australia. The area along the south central coast is called the Nullarbor Plain. The Nullarbor is a vast, arid, limestone plateau that is virtually uninhabited. It has an extensive system of caverns, tunnels, and sinkholes that contain valuable geological information about life in ancient Australia. Extinct volcanic craters are located in the southeastern part of South Australia and in Victoria.
The coastline of Australia measures some 25,760 km (16,010 mi). It is generally regular, with few bays or capes. The largest inlets are the Gulf of Carpentaria in the north and the Great Australian Bight in the south. The several fine harbors include those of Sydney, Hobart, Port Lincoln, and Albany.
The Great Barrier Reef is the largest known coral formation in the world. It extends some 2,010 km (some 1,250 mi) along the eastern coast of Queensland from Cape York in the north to Bundaberg in the south. The chain of reefs forms a natural breakwater along the coast for vessels of modest size but is sometimes hazardous for larger ships.