Australia's Drift: Earth Movement Tectonic Processes
Continental drift
The broad shape of Australia and its distinctive landforms have been influenced over long periods by earth movements that cause the breaking and bending of the Earth's crust. Geographers call these movements tectonic processes.
The Earth's crust is made up of many individual moving pieces called tectonic plates. There are nine large plates and about a dozen smaller ones. The larger plates contain the continents and oceans. These plates ‘float’ on the dense layer of rock below.
Geographers have long been aware that, if the continents were rearranged and repositioned, they would fit together like a jigsaw. Scientists believe that, about 225 million years ago, the continent of Australia was joined to all the other continents. …show more content…
The Earth is about 4600 million years old and the Australian continent is about 4300 million years old. Over millions of years, Australia has undergone many changes — mountain ranges and inland seas have come and gone. As mountain ranges eroded, sediments many kilometres thick were laid down over vast areas. These sedimentary rocks were then subjected to folding, faulting and uplifting. Over time, the forces of weathering and erosion wore these down again. Erosion acts more quickly on softer rocks, forming valleys and bays. Harder rocks remain as mountains, hills and coastal …show more content…
The Murray–Darling is Australia's largest river system. Other significant rivers are: the Burdekin River in Queensland the Hunter River in New South Wales the Murchison, Gascoyne, Ashburton, Fortescue, De Grey, Fitzroy, Drysdale and Ord rivers in the north-west region the Victoria and Daly rivers in the Northern Territory the Leichhardt, Norman, Gilbert and Mitchell rivers in the Gulf of Carpentaria the Tamar, Derwent and Gordon rivers of Tasmania, although these are relatively short.
Australia has many lakes but they hold little water compared with those found on other continents. The largest are Lake Eyre and Lake Torrens in South Australia. During dry seasons, these become beds of salt and mud. Yet an inland sea did once exist in this area. It covered about 100 000 square kilometres around present-day Lake Eyre and Lake Frome. South Australia is Australia's driest state and has very few permanent rivers or streams.
Satellite image of Lake Eyre, March 1985. Once a freshwater lake, the region is now normally an evaporated saltpan. The crust of salt is shown as white in the image.Satellite image of Lake Eyre, February 1984. Three or four times each century, the lake fills with water, transforming it into a haven for wildlife. Deep water is shown as black in the
The broad shape of Australia and its distinctive landforms have been influenced over long periods by earth movements that cause the breaking and bending of the Earth's crust. Geographers call these movements tectonic processes.
The Earth's crust is made up of many individual moving pieces called tectonic plates. There are nine large plates and about a dozen smaller ones. The larger plates contain the continents and oceans. These plates ‘float’ on the dense layer of rock below.
Geographers have long been aware that, if the continents were rearranged and repositioned, they would fit together like a jigsaw. Scientists believe that, about 225 million years ago, the continent of Australia was joined to all the other continents. …show more content…
The Earth is about 4600 million years old and the Australian continent is about 4300 million years old. Over millions of years, Australia has undergone many changes — mountain ranges and inland seas have come and gone. As mountain ranges eroded, sediments many kilometres thick were laid down over vast areas. These sedimentary rocks were then subjected to folding, faulting and uplifting. Over time, the forces of weathering and erosion wore these down again. Erosion acts more quickly on softer rocks, forming valleys and bays. Harder rocks remain as mountains, hills and coastal …show more content…
The Murray–Darling is Australia's largest river system. Other significant rivers are: the Burdekin River in Queensland the Hunter River in New South Wales the Murchison, Gascoyne, Ashburton, Fortescue, De Grey, Fitzroy, Drysdale and Ord rivers in the north-west region the Victoria and Daly rivers in the Northern Territory the Leichhardt, Norman, Gilbert and Mitchell rivers in the Gulf of Carpentaria the Tamar, Derwent and Gordon rivers of Tasmania, although these are relatively short.
Australia has many lakes but they hold little water compared with those found on other continents. The largest are Lake Eyre and Lake Torrens in South Australia. During dry seasons, these become beds of salt and mud. Yet an inland sea did once exist in this area. It covered about 100 000 square kilometres around present-day Lake Eyre and Lake Frome. South Australia is Australia's driest state and has very few permanent rivers or streams.
Satellite image of Lake Eyre, March 1985. Once a freshwater lake, the region is now normally an evaporated saltpan. The crust of salt is shown as white in the image.Satellite image of Lake Eyre, February 1984. Three or four times each century, the lake fills with water, transforming it into a haven for wildlife. Deep water is shown as black in the