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).
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
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.
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