Coral Island
The ocean is a large reservoir of salty water. The ocean is used as a habitat for different kinds of animals and plants. Whales, dolphins, fishes, crabs, etc. are examples of animals living in the ocean. Among the plants, there are algae and seaweed.
A coral island is a type of island formed from coral waste materials or rubbish and loose decaying material.
It occurs in tropical and sub-tropical areas, typically as part of a coral reef that has grown to cover a far larger area under the ocean.
Coral reefs are some of the oldest ecosystems on the earth, over geological time forming massive reefs of limestone.
The reef environment supports more plant and animal species than any other habitat.
Coral reefs are vital for life in multiple aspects some of which include structure, ecology, and nutrient cycles which all support biodiversity in the reefs.
Coral reefs build massive calcareous skeletons that serve as homes for animals such as fish hiding inside the crooks and crannies of the reef and small sea creatures with shells attaching themselves directly to the coral’s structure.
The structures also help plants that need the sun to photosynthesize, by lifting the plants to the ocean’s surface where the sunlight can penetrate the water.
The structures also create calm zones in the ocean providing a place for fish and plant species to survive.
Australia is situated entirely in the southern hemisphere and is often referred to as 'the land down under'. the name 'Australia' comes from the Latin word 'australis' meaning southern. The country's official name is the Commonwealth of Australia.
Australia is unique because it is the only country that extends over an entire continent. It is the sixth largest country in the world but is the smallest continent. Other popular names for this country are the 'Island continent', 'Continent State', 'One-country Continent', and the 'Land of Migrants'.
'THE GREAT BARRIER REEF'
The Great Barrier Reef is a 2,300 km long underwater ridge-like feature off the northeast to 240 km from the coastline. It is composed of millions and millions of shells of tiny marine creatures called coral polyps. When corals die their hard skeletons remain fixed in place. Since these polyps live in colonies when they die their large accumulation of skeletons forms coral reefs which are circular or ridge-like. The Great Barrier Reef is Australia's biggest tourist attraction. The warm, shallow, salty sea between the reef and the shore is the home of tropical fish of bright colors, and crustaceans that abound in this underwater paradise. However, in the past, the Great Barrier Reef was a great danger to navigators.
Location:
Australia lies between the Indian Ocean in the west and the South Pacific Ocean in the east. The Arafura Sea lies to its north. The large water body south of Australia is the Southern Ocean. This island continent lies southeast of mainland Asia and extends from 114०E to 154०E. It is latitudinal extend is 10०S to 40०S. The tropic of Capricorn or 23½०S latitude passes through the middle of the continent.
Physical Features:
The continent of Australia can be divided into three broad physical regions. From east to west they are:
a) The Eastern Highlands:
The highlands extend from Cape York in the north to Tasmania in the south and lie roughly parallel and very close to the east coast of Australia. The mountains are broad and low in the north but narrow and high in the south. The mountainside facing the east is sleep but the side facing the west slopes gently towards the Central Lowlands.
These highlands are called the Gregory Range in Queensland, the Blue Mountains, and the New England Range in New South Wales. In Victoria, they are called the Australia Alps. The highest peak of the Eastern Highlands is Mt Koscuszko, which is 2,228 m above sea level. It lies in the Australian Alps. The Eastern Highlands are also called the Great Dividing Range because the mountains form the main watershed of Australia. A number of Australia's principal rivers originate here. The Snowy River flows down the steep eastern slope while the Darling, Lachlan, and Murrumbidgee Rivers flow down the western slope and join the Murray River.
b) The Central Lowlands:
The lowlands are a rainless flat low-lying area between the Eastern Highlands and the Western Plateau. They extend from the Gulf of Carpentaria in the north to Encounter Bay in the south forming the world's largest artesian basin. in an artesian basin. In an artesian basin, a layer of porous or pervious rock acts as a reservoir. The rainwater that seeps underground is trapped in the previous layer which becomes an aquifer - a layer of rock capable of holding water and allowing it to pass through. When a well is bored into the aquifer, the water, which is under pressure, gushes out spontaneously. This well is called an artesian well.
The Central Lowlands can be divided into three distinct divisions - the Carpentaria Lowlands, the Lake Eyre Basin, and the Murray-Darling Basin. Lake Eyre is the world's largest area of inland drainage, i.e., the rivers flowing in this area do not reach the sea.
