Land and water are distributed over Earth's surface non-uniformly. Australia shares with Antarctica the ocean hemisphere which embraces most of the Southern, Indian and Pacific Oceans. Northwards, Papua New Guinea and the Indonesian Archipelago bridge the gap to Asia. In all remaining directions, wide stretches of deep water separate Australia from other land masses. This configuration has not changed for a very long time and is responsible for the development of Australia's unique fauna and flora, which were affected deeply by the European invasion.
Australia's most northerly point lies on Torres Strait, about l0º South of the Equator, her most southerly point is the tip of Tasmania on the Southern Ocean, more than 33º of Latitude away. Her most westerly point lies on the Indian Ocean near Shark Bay, 113º East of Greenwich, her most easterly point in northern New South Wales, on the Pacific Ocean, 40º of Longitude to the East.
Northern Australia is exposed to global monsoonal winds, her Southern coast to outcrops of the Antarctic Ocean's Roaring Forties. Australia's concentrated land mass exerts its own influence on the winds along the coast. Firstly, land and sea breezes alternate daily almost all the year round. Secondly, the temperature differential between the interior of the continent and the surrounding oceans induces her own, monsoonal type winds which are especially pronounced over the southern region.
Associated with these meteorological phenomena and other such processes further afield, changes in local sea levels are superimposed on the astronomical tides. The astronomical tides are modulated by the greatly varying width of Australia's continental shelf and are by far the most dramatic event occurring along Australia's coast, so that a thorough knowledge of the tides is vital for many activities. Along the South-West and South Coasts, the meteorological tides are large and add an unpredictable element to shore conditions. Occasional disturbances such as cyclones may overshadow the tides in the North for brief periods without essentially affecting their basic rhythm.
Strong currents flow along large sections of Australia's coast and have major roles in the formation of local climate and seasons, pollution, air-sea searches, fishing and so on. By 1970, these currents have been studied only in a haphazard manner, and the mechanisms of their formation and their seasonal variations are not fully understood.
A detailed knowledge of storm waves is most important for the design of coastal installations and shore protection methods. Unfortunately, systematic recording of waves around Australia's coast is still sporadic. Generated in the Roaring Forties, long waves with periods in excess of 25 seconds reach certain sections of the South Coast between Bundaberg and Shark Bay as well as the far-away shores of America and Europe. Their occurrence in time still awaits systematic study.
Heavy concentrations of population over relatively short segments of the East, South and West Coasts and of mining activities around Australia's perimeter have led to as yet uncoordinated observational programs. The importance of environmental considerations has increased sharply, but this page has had no access to results of recent efforts.
Long sections of Australia's coast are readily reached by growing numbers of tourists whose effects cannot be overestimated. However, extensive sections, intersected by deep gulfs or lined by steep cliffs, still remain in their primeval state. Tourism need be made aware of the importance of looking responsibly after the coast, in order to conserve the marine environment for future generations.