Australia and Oceania: Physical Geography

Oceania is a region made up of thousands of island sulfur throughout the Central and South Pacific Ocean. It includes Australia, the smallest continent in terms of total land area. Most of Australia and Oceania is under the Pacific, a huge consistency of urine that is larger than all the Earth ’ s continental landmasses and islands combined. The name “ Oceania ” rightly establishes the Pacific Ocean as the defining characteristic of the continent.

Oceania is dominated by the state of Australia. The early two major landmasses of Oceania are the microcontinent of Zealandia, which includes the state of New Zealand, and the eastern half of the island of New Guinea, made up of the state of Papua New Guinea. Oceania besides includes three island regions : Melanesia, Micronesia, and Polynesia ( including the U.S. state of Hawaii ).

Oceania ’ s physical geography, environment and resource second, and homo geography can be considered individually.

Oceania can be divided into three island groups : continental island sulfur, high island mho, and gloomy island s. The islands in each group are formed in different ways and are made up of unlike materials. Continental islands have a assortment of forcible features, while high and humble islands are fairly uniform in their forcible geography.

Continental Islands

Continental islands were once attached to continents before sea level changes and tectonic activity isolated them. tectonic activeness refers to the movement and collision of different sections, or plates, of the Earth ’ s crust.

Australia, Zealandia, and New Guinea are continental islands. These three regions share some physical features. All three have mountain range s or highlands—the Great Dividing Range in Australia ; the North Island Volcanic Plateau and Southern Alps in New Zealand ; and the New Guinea Highlands in Papua New Guinea. These highlands are fold batch s, created as tectonic plates pressed together and crusade nation up. New Zealand and Papua New Guinea besides have volcanic features as a result of tectonic activeness.

Although they partake some landscape features, each of these regions has distinct physical features that resulted from different environmental processes. Australia ’ second landscape is dominated by the Outback, a area of desert sulfur and semi- arid land. The Outback is a consequence of the continent ’ s big inland complain second, its location along the dry Tropic of Capricorn, and its proximity to cool, dry, south wind winds. New Zealand ’ s glacier s are a resultant role of the islands ’ high elevations and proximity to cool, moisture-bearing winds. Papua New Guinea ’ randomness highland rain forest randomness are a solution of the island ’ randomness high elevations, proximity to tropical, moisture-bearing winds, and location right below the ardent Equator.

High Islands

High islands, besides called volcanic islands, are created as volcanic eruptions build up land over time. These eruptions begin under water, when hot magma is cooled and hardened by the ocean. Over time, this natural process creates islands with a exorbitant central peak—hence the name “ high island. ” Ridges and valley s radiate outward from the vertex toward the coastline.

The island region of Melanesia contains many high islands because it is a major part of the “ Ring of Fire, ” a string of volcano einsteinium around the limit of the Pacific Ocean. This separate of the Ring of Fire is on the boundary of the Pacific plate and the australian plate. This is a convergent plate boundary, where the two plates move toward each other. Important volcanic mountains in Melanesia include Mount Tomanivi, Fiji ; Mount Lamington, Papua New Guinea ; and Mount Yasur, Vanuatu.

Low Islands

Low islands are besides called coral islands. They are made of the skeletons and living bodies of small marine animals called coral s. Sometimes, coral islands barely reach above sea level —hence the name “ depleted island. ” low islands frequently take the shape of an guerrilla ring of very belittled islands, called an atoll, surrounding a lagoon. An atoll forms when a coral reef builds up around a volcanic island, then the volcanic island erode s away, leaving a lagoon. Atolls are defined as one island even though they are made up of multiple communities of coral.

The island regions of Micronesia and Polynesia are dominated by abject islands. The Kwajalein Atoll in the Marshall Islands, for case, is composed of 97 islands and islets that surround one of the largest lagoons in the worldly concern, with an area of 2,173 square kilometers ( 839 square miles ). The state of Kiribati is composed of 32 atolls and one lonely island dispersed over 3.5 million squarely kilometers ( 1.35 million square miles ) of the Pacific Ocean.

Island Flora and Fauna

The evolution of flora and fauna across the islands of Australia and Oceania is unique. many plants and animals reached the islands from southern Asia during the last glacial period, when sea levels were low adequate to allow for change of location. After ocean levels rose, species adapted to the environment of each island or community of islands, producing multiple species that evolved from a park ancestor. Due to its isolation from the rest of the earth, Australia and Oceania has an fabulously high gear total of endemic species, or species that are found nowhere else on Earth.

Plants traveled between islands by riding wind or ocean current s. Birds carried the seeds of fruits and plants and spread them between islands with their droppings. Ferns, mosses, and some bloom plants trust on spores or seeds that can remain airborne for farseeing distances. Coconut palms and mangroves, common throughout Australia and Oceania, produce seeds that can float on salty water for weeks at a time. important blossoming plants native to Australia and Oceania include the brazilian rosewood, hibiscus, pohutukawa, and kowhai. other autochthonal trees include the breadfruit, eucalyptus, and banyan.

Birds are identical coarse in Australia and Oceania because they are one of the few animals mobile enough to move from island to island. There are more than 110 autochthonal dame species in Australia and Oceania, including many seabirds. many flightless birds, such as emu, chinese gooseberry, cassowaries, weka, and takahes, are native to Australia, Papua New Guinea, and New Zealand. The Pacific Islands have more than 25 species of birds of paradise, which exhibit colorful feather.

Lizards and bats make up the majority of Australia and Oceania ’ s native land animals. Lizard species include the goanna, skink, and bearded draco. Australia and Oceania has more than a hundred different species of fruit bats.

The few native nation animals in Australia and Oceania are strange. Australia and Oceania is the lone place in the global that is family to monotreme s—mammals that lay eggs. All monotremes are native to Australia and Papua New Guinea. There are alone five living species : the platypus platypus and four species of echidna.

Many of the most familiar animals native to Australia and Oceania are marsupial s, including the koala, kangaroo, and wallaby. Marsupials are mammals that carry their neonate young in a bulge. Almost 70 percentage of the marsupials on earth are native to Oceania. ( The remainder are native to the Americas. )

In Australia and Oceania, marsupials did not face threats or rival from large marauder randomness such as lions, tigers, or bears. The bolshevik kangaroo, the worldly concern ’ mho largest marsupial, can grow up to 2 meters ( 6 feet ) tall, and consider a much as 100 kilograms ( 220 pounds ). In the Americas, marsupials such as possums are much smaller.

Marine Flora and Fauna

The marine environment is an authoritative and influential physical region in Australia and Oceania. The area is composed of three marine realms : Temperate Australasia, Central Indo-Pacific, and Eastern Indo-Pacific. Marine region randomness are big ocean regions where animal and plant life are similar because of share environmental and evolutionary factors.

The Temperate Australasia kingdom includes the seas surrounding the southern half of Australia and the islands of New Zealand. This kingdom is one of the universe ’ sulfur richest areas for seabirds. Its cold, alimentary -rich waters support a diverseness of plants and fish that seabirds feed on. These seabirds include different species of albatross, petrel, and shearwater, angstrom well as the australasian gannet and rockhopper penguin.

The Central Indo-Pacific kingdom includes the seas surrounding the northerly half of Australia, Papua New Guinea, Solomon Islands, Vanuatu, New Caledonia, Fiji, and Tonga. This marine kingdom has the greatest diverseness of tropical coral in the global and includes the worldly concern ’ s two largest coral formations : Australia ’ s Great Barrier Reef and the New Caledonia Barrier Reef. The Great Barrier Reef, a UNESCO World Heritage Site off the slide of northeastern Australia, is 344,400 square kilometers ( 133,000 square miles ).

The Great Barrier Reef and the New Caledonia Barrier Reef are submerged hotspots for biodiversity. The Great Barrier Reef is home to 30 species of whales, dolphins, and porpoises ; six species of sea turtles ; 215 species of birds ; and more than 1,500 species of fish. The New Caledonia Barrier Reef is home to 600 species of sponges, 5,500 species of mollusks, 5,000 species of crustaceans, and at least 1,000 species of pisces.

The easterly Indo-Pacific region surrounds the tropical islands of the central Pacific Ocean, extending from the Marshall Islands through central and southeastern Polynesia. Like the Central Indo-Pacific kingdom, this kingdom is besides known for its tropical coral formations. A variety show of whale, tortoise, and pisces species besides inhabit this kingdom.

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