1 / 17

Coasts

Coasts

Télécharger la présentation

Coasts

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Coasts A coast or coastal area is the areas of land and sea bordering the shoreline and extending seaward through the breaker zone. Coastal areas throughout the world are under enormous environmental stress, which is caused by a wide range of factors, including pollution and the destruction and deterioration of marine habitats. Location: Due to coasts bordering countries, they are located on the edge of the majority of the world's continents. Australia's most utilised coast is the East coast of Australia where fishing, recreation and tourism are some of the main activities that occur here.

  2. Coral Reefs A coral reef is a wave-resistant structure resulting from cementation processes and the skeletal construction of hermatypic corals, calcareous algae, and other calcium carbonate-secreting organisms. Coral reefs are warm, clear, shallow ocean habitats that are rich in life. The reef's massive structure is formed from coral polyps, tiny animals that live in colonies; when coral polyps die, they leave behind a hard, stony, branching structure made of limestone. Location: Coral reefs develop in shallow, warm water, usually near land, and mostly in the tropics; coral prefer temperatures between 21 - 30 °C. There are coral reefs off the eastern coast of Africa, off the southern coast of India, in the Red Sea, and off the coasts of northeast and northwest Australia and on to Polynesia. There are also coral reefs off the coast of Florida, USA, to the Caribbean, and down to Brazil. Australia's largest and most well known Coral Reef is the Great Barrier Reef, it is also the largest in the world.

  3. Deserts Deserts cover about one fifth of the Earth’s surface and occur where rainfall is less than 50 cm/year. Most deserts have a considerable amount of specialized vegetation, as well as specialized vertebrate and invertebrate animals. Soils often have abundant nutrients because they need only water to become very productive and have little or no organic matter. There are relatively few large mammals in deserts because most are not capable of storing sufficient water and withstanding the heat. Deserts often provide little shelter from the sun for large animals. The dominant animals of warm deserts are nonmammalian vertebrates, such as reptiles. Mammals are usually small, like the kangaroo mice of North American deserts. There are four major types of deserts:Hot and Dry, Semiarid, Coastal, Cold.

  4. Deserts (2) Some locations of deserts include: (Hot): - North America, West Coast of South America, Central Australia North Africa, Middle East (Sahara). Cold – Antarctic, Central Asia, Greenland. Spatial Distribution: Deserts cover about 35% of the world’s surface and about 2/3rd’s of Australia. There are two types of deserts hot deserts and cold deserts. Hot deserts: Are located in sub-tropical areas. ie: The Sahara Desert in Africa covers an area of 9 million sqkms. Cold deserts: ie: the Gobi desert in Asia, cold deserts are found on high plateaus and Polar Regions. Antarctica is the world’s largest desert.

  5. Deserts (3) Human Interaction in Deserts: -Very few people settled in deserts due to their harsh climates. - People that do live in deserts live in small settlements although places like Cairo in Egypt are large. - Graziers live in desert, who are nomadic (always moving from place to place) and farmers where irrigation is accessible. - Tourist towns and military bases are also human interactions in deserts. - Aborigines were the first people to live in Australia’s desert environment. They hunted and gathered food and resources in the desert.

  6. Deserts (4) Major Geographical Processes that operate within Deserts: -Atmospheric-Hot deserts, just to the North and South of the Equator, have higher maximum temperatures than tropical rainforests, which are closer to the equator. This is due to less cloud cover to block out sun’s rays. Altitude also affects temperature and distance from the sea. Deserts are in arid zones, where vegetation does not form a complete ground cover and there is a large loss of moisture from evaporation. Deserts are located in regions were the air is mostly warm and dry, where little rain is produced. - Biotic- Desert vegetation in deserts has to adapt to lack of water. The two main types of desert vegetation are Perennials and Ephemerals. Perennials store water ie: cactus. Ephemerals have short life cycle and avoid drought this way. Desert animals have also made adaptations, their features and behaviour have become suited to desert life ie: bilby, desert crab, camels. - Geomorphic-Desert landforms are formed by a combination of three main processes: weathering (break down of bare rock by water and heat), erosion (removes material such as weathered rock caused by running water and wind) and deposition (wind/water slow down so they can no longer transport materials-which are deposited). - Hydrologic- There is a shortage of moisture in deserts because of low precipitation. There are also long periods between rain.

  7. Grasslands Grasslands are characterized as lands dominated by grasses rather than large shrubs or trees. In the Miocene and Pliocene Epochs, which spanned a period of about 25 million years, mountains rose in western North America and created a continental climate favorable to grasslands. Ancient forests declined and grasslands became widespread. There are two main divisions of grasslands: tropical grasslands (called savannas), and temperate grasslands. Location: Almost one-fourth of the Earth's land area is grassland. Grasslands are located in North America's interior, in south eastern South America, in Eurasia, in Africa, and in Australia and New Zealand.

  8. King Tides During the twentieth century, the atmosphere warmed up by 0.5°C, a trend that is expected to continue. There is growing evidence that human activities, such as burning fossil fuels and cutting down trees, has contributed to global warming. Climate change could cause changes to global environments in the following ways: · melting of the polar icecaps and the retreat of glaciers in mountain lands · rising sea levels and massive flooding of low lying areas · higher tides and more violent storms · disruption to agriculture and changes to natural habitats.

  9. King Tides (2) How and when are these created? King tide is the popular name for an especially high tide. The phrase is used mostly in Australia and other Pacific nations. In the lunar month, the highest tides occur roughly every 14 days, at the new and full moons, when the gravitational pull of the moon and the sun are in line. These are called spring tides. On Australia's East Coast, the highest tides occur during the winter months of June, July and August, and the summer months of December, January and February. The highest of each of these periods (i.e., one in winter and one in summer, totaling two per year) are known as the king tides. The winter king tide usually occurs at night and therefore goes unnoticed. Consequently the summer king tide usually catches the most attention. On such days the surf is particularly dangerous — tall waves, long clean breaks, strong rips, consistent sets: ideal for surfing, but seductive and dangerous for inexperienced swimmers.

  10. King Tides (3) King tides are particularly formidable on the island of Tuvalu, where they can devastate the low lying atoll's people and wildlife. Climate change and the associated sea level rise may exacerbate these effects. As with all spring tides, king tides occur with the coming of new and full moons. Tuvalu is Tuvalu formerly known as the Ellice Islands, is a Polynesian island nation located in the Pacific Ocean, midway between Hawaii and Australia. Its nearest neighbours are Kiribati, Nauru, Samoa and Fiji. It comprises four reef islands and five true atolls. Its population of 12,373 makes it the third-least-populated sovereign state in the world, with only Vatican City and Nauru having fewer inhabitants. In terms of physical land size, at just 26 square kilometres Tuvalu is the fourth smallest country in the world, larger only than the Vatican City at 0.44 km2 , Monaco at 1.95 km2 and Nauru at 21 km2. (As a comparison: Singapore is 683 sq kilometres and Coffs Harbour 1172 sq kilometres).

  11. Mountains Mountains cover about a fifth of the earth's surface, mountains are found on all continents and there are even mountains under the surface of the sea. Mountains are formed by slow but gigantic movements of the earth's crust. Sometimes the crust has folded and buckled, sometimes it breaks into huge blocks. In both cases, great areas of land are lifted upwards to form mountains. Other mountains are formed by the earth's crust rising into a dome, or by volcanic activity when the crust cracks open. Mount Everest is the largest mountain in the world and Mount Kosioskco is the largest in Australia.

  12. Polar Lands Polar lands are broadly located inside the Arctic and Antarctic circles, but extend towards the equator south of the Arctic circle in the northern hemisphere. The boundary of the polar lands is generally regarded as the isotherm where the mean temperature of the warmest month is no more than 10`C. On the surface there is no vegetation and permanent ice cover. Polar lands are considered to have the most desolate and harsh environment on Earth.

  13. Rainforests Rainforests are very dense, warm, wet forests. They are havens for millions of plants and animals. Rainforests are extremely important in the ecology of the Earth. The plants of the rainforest generate much of the Earth's oxygen. These plants are also very important to people in other ways; many are used in new drugs that fight disease and illness. Tropical rainforests are located in a band around the equator, mostly in the area between the Tropic of Cancer (23.5° N latitude) and the Tropic of Capricorn (23.5° S latitude). This 4800 km wide band is called the "tropics." Tropical rainforests are found in South America, West Africa, Australia, southern India, and Southeast Asia.

  14. Rivers (left – Murray River) (right – Yangtze – the long - River A river is fresh water flowing across the surface of the land, usually to the sea. It flows in a channel. The bottom of the channel is called the bed and the sides of the channel are called the banks. Rivers begin in mountains or hills, where rain water or melting snow collects and forms tiny streams called gullies. Gullies either grow larger when they collect more water and become streams themselves or meet streams and add to the water already in the stream. Some main rivers of the world and their locations are: Amazon -South America, Zambezi –Africa, Volga –Russia, Yangtze -China Severn – Britain, Thames –England, Mississippi -United States

  15. Tundra There are two types of tundra in the world, Arctic and Alpine. The arctic tundra is at the top of the world around the North Pole. The tops of tall cold mountains are alpine tundra. The most distinctive characteristic of the tundra soil is its permafrost, a permanently frozen layer of ground often 2000 feet thick. Shallow rooted tundra plants and microorganisms grow in the permafrost. Animals are adapted to handle cold winters and to breed and raise young quickly in the short summers. Average yearly temperatures range from -57 degrees to -7 degrees. Tundra can be found in the high northern latitudes of the world. he most common animals found in the tundra are the Caribou, Reindeer, and the Lemming.

  16. Wetlands Wetlands are areas of standing water that support aquatic plants. Marshes, swamps, and bogs are all considered wetlands. Plant species adapted to the very moist and humid conditions are called hydrophytes. These include pond lilies, cattails, sedges, tamarack, and black spruce. Wetlands have the highest species diversity of all ecosystems. Many species of amphibians, reptiles, birds (such as ducks and waders), and furbearers can be found in the wetlands. Wetlands are not considered freshwater ecosystems as there are some, such as salt marshes, that have high salt concentrations—these support different species of animals, such as shrimp, shellfish, and various grasses.

More Related