Continent and state of Australia
Australia is the only country in the world that spans an entire continent. Australia is the smallest of the continents of the earth and makes up the largest part of the land mass of Oceania. Its largest east-west distance is about 4500 km, the north-south extension is about 3600 km.
Australia’s geological construction is straightforward because it only comprises three major areas: West Australian Tablelland, the Central Australian Depression and the East Australian Highlands. Australia is the driest continent on earth. The amount of precipitation decreases towards the interior of the continent. In the center, deserts and semi-deserts shape the landscape.
The population density is very low at 2.5 inhabitants/km². Traditionally, agriculture, especially sheep and cattle breeding, is the most important industry in Australia. The mining sector is becoming increasingly important due to the export of raw materials.
The Aborigines, the indigenous people of the country, have been persecuted by the Europeans since the settlement and almost exterminated. A policy of reparation tries to integrate it into the social structure of the country.
With an area of 7.7 million km², Australia is the smallest of the continents of the world and comprises the largest part of the land mass of Oceania. The island of Tasmania to the south and a large number of other islands belong to the state of Australia.
Australia extends on both sides of the southern tropic between about 10 ° NB and 40 ° S. B. Its largest east-west extension is approximately 4500 km, the largest north-south distance 3600 km.
The coasts of the continent are relatively weakly structured: the Great Barrier Reef is located in front of the northern part of the east coast in the shallow sea. With a length of 2000 km and its countless islands, it is the largest living coral reef on earth. The continent is surrounded by deep sea on the other three sides. In the north, it separates Lake Arafura and Timor from New Guinea and the island world of Indonesia. The west and south coasts are washed by the Indian Ocean. In the southeast, the Tasman Sea separates Australia from neighboring New Zealand. The Pacific Ocean with the coral lake in the northeast finally borders Australia in the east (Fig. 1).
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The geological subsurface of large parts of Australia dates back to ancient times. This ancient landmass of the Australian shield was part of the former primary continent of Gondwana. Since the disintegration of Gondwana in the Jura, the Australian plaice has drifted in a southeasterly direction and has been an independent continent ever since. The construction of this continent is relatively simple, because it consists of only three metropolitan areas, the West Australian Shield, the Central Australian Valley and the East Australian Highlands (Fig. 2).
The Western Australian Shield stretches west of about 135 ° O.L. and thus covers more than half of the continent. It mainly consists of table countries at altitudes between 300 and 500 m. With a few exceptions, these table countries are semi-desert or desert-like in character. In its central part, the Great Sand Desert, the Gibson Desert and the Great Victoria Desert follow from north to south.
The space between the Great Victoria Desert and the Indian Ocean is finally occupied by the Nullabor level, a semi-desert-like treeless flatland. The table countries of the Australian Shield are interspersed with mountains, for example the MacDonnel chain in the center of Australia, all of which only reach low mountain ranges around 500 m. The Central Australian Valley consists of several basin landscapes that represent flat-hilly plains. They are usually less than 150 m and are crossed by many, usually dry river beds. In the north, around the Carpentaria golf, is the first basin of the same name.
The Great Artesian Basin occupies the center of the continent. It is the driest basin with the Simpson Desert, in which the sand dunes reach heights of up to 60 m, in the northern part and Lake Eyre in the southern part.
In the very south of the Central Australian Valley lies the Murray Basin, which is almost enclosed by mountains and through which the largest Australian currents flow.
The mountain ranges of the East Australian highlands, the Great Dividing Range, extend over 3000 km parallel to the Pacific coast of Australia. Steep drops to the coast and inland as well as deeply cut rivers characterize these landscapes. The majority of the mountain ranges are low mountain ranges. Only in the south, in the Canberra area, do they have the character of high mountains. Here, in the Snow Mountains, is Mount Kosciusko (2230 m), the highest mountain in Australia.
The only major river in Australia that constantly carries water is the Murray in southeast Australia. It rises in the Snowy Mountains. West of Adelaide it flows into the Indian Ocean after 2589 km.
The longest river, however, is the Darling River at 2720 km, but in dry years it carries very little, sometimes no water at all.
In the Great Dividing Range, there are still a large number of rivers that flow into the Pacific after a few hundred kilometers. The numerous smaller rivers that originate in the Great Artesian Basin mostly end in Lake Eyre, which is 14 m above sea level. d. M. lies and thus represents the lowest point in Australia.
This largest lake in Australia is located in the driest and hottest region on the continent. The rivers that flow into the lake have therefore dried up for months and rarely fill it. Due to the high evaporation, Lake Eyre is a salt lake, the area of which fluctuates between 15000 and 8500 km². There are numerous other salt lakes in central Australia.
Ranked by Countryaah, Oceania is the driest and second smallest continent on earth. The southern tropic divides Australia into a northern part with a tropical climate and into a central and southern part with a subtropical and, in the very south, temperate climate (Figure 6). The tropical north has high temperatures all year round and receives significant rainfall with an average of 1500 mm per year. The precipitation falls almost exclusively in the summer rainy season from November to April.
To the south inland, however, they decrease rapidly. Already 1000 km south of Darwin only 350 mm fall per year. In the subtropics, the mid-coast areas of the continent are on the Pacific coast in the east (e.g. Brisbane) and on the coast of the Indian Ocean in the west (e.g. Perth).
With around 1100 mm of rainfall per year, there is no pronounced dry season in these areas. In the mountain regions of the Great Dividing Range, which are over 2000 m high, up to 3500 mm of precipitation falls per year, in the south as snow in winter.
The annual temperature differences vary between an average of 25 °C in January (summer) and 15 °C in July (winter), so they are relatively small. The south of Australia around Sydney and Melbourne has a temperate climate that is comparable to the European Mediterranean climate. Mild, wet winters alternate with warm, dry summers. The areas of central Australia, the so-called outback, have a special climatic position. Characteristic here are high temperature fluctuations between day and night and extreme drought. Temperature “jumps” from frosty minus degrees at night to hot 40 °C the next day are not unusual in the outback.
The vegetation of Australia is fundamentally different from that of other continents. Around 2,200 plant species have only developed in Australia, which means that they are endemic. Tropical rainforests are still growing in the humid tropical north and northeast.
To the south inland, tree, bush and grass savannahs join with increasing drought. They then pass into the Australian scrub, which dominates large parts of the inhospitable interior. It mainly consists of evergreen hardwood and shrub plants.
In the central parts of the continent, the scrub finally turns into deserts and semi-deserts with tufted grasses (Spinifex).
The most characteristic endemic plants in Australia are the diverse eucalyptus species. Common to all of them is the characteristic of not throwing off their leaves but their bark in the dry or cold period. Bottle trees and grass trees, cassowaries and, above all, various types of acacia are characteristic of Australia.