Oceans Introduction
Our Planet could well be called Oceania, as the area occupied by water, 2.5 times the area of land. Ocean water cover almost three quarters of the globe layer thickness of about 4000 m, accounting for 97% of the hydrosphere, while the waters of land contain only 1%, and in glaciers constrained by only 2%.
Oceans, being the aggregate of all the seas and oceans of the Earth, has a huge impact on the life of the planet. The huge mass of ocean water generates the planet's climate, is a source of precipitation. From it receives more than half of the oxygen, and it also regulates the content of carbon dioxide in the atmosphere, since it is able to absorb the excess. At the bottom of the ocean there is an accumulation and transformation of the great mass of mineral and organic substances, so the geological and geochemical processes occurring in the oceans and seas, have a very strong impact on the Earth's crust.
It was the cradle of the ocean of life on Earth, and now it is home to about four-fifths of all living beings of the planet.
Ocean resources
In our time, the era of global issues, the oceans plays an increasingly important role in the life of mankind. Being a huge pantry mineral, energy, plant and animal resources, which - with their rational consumption, and artificial reproduction - can be almost unlimited, Ocean is able to solve some of the most urgent challenges ahead: the need for a rapidly growing population with food and raw materials for developing industry, risk of an energy crisis, a lack of fresh water.
The main resource of the oceans - sea water. It contains the 75 chemical elements of which are important, such as uranium, potassium, bromine and magnesium. Although the main product of seawater is still salt - 33% of world production, but mined magnesium and bromine, have long patented methods for a variety of metals, including copper and essential industry and silver reserves are steadily being depleted, while in the ocean their waters contain up to half a billion tons.
In connection with the development of nuclear power, there are good prospects for the extraction of uranium and deuterium from the waters of the oceans, especially since uranium ore reserves on earth are reduced and the Ocean of his $ 10 billion tons, deuterium has practically inexhaustible - for every 5,000 ordinary hydrogen atoms have one heavy atom. In addition to the release of chemical elements sea water can be used to obtain the necessary human fresh water. Now available in many industrial desalination methods: Use chemical reaction in which impurities are removed from the water, the salt water is passed through special filters, and finally, the hands are boiling. But desalination is not the only way to get potable water.
Bottom There are sources that are more frequently found on the continental shelf, that is, in the areas of the continental shelf adjacent to the shores of the land and it has the same geological structure. One of these sources, located off the coast of France - Normandy, gives the amount of water that they call it an underground river.
Mineral resources of the oceans are not only sea water, but also the fact that under water. Bowels of the ocean and its bottom is rich in mineral deposits. Are located on the continental shelf of the coastal alluvial deposits - gold, platinum, and precious stones are found - rubies, diamonds, sapphires, emeralds. For example, near the Namibian diamond design are underwater gravel since 1962. On the shelf and continental slope partially Ocean has large deposits of phosphate, which can be used as fertilizer, and the reserves will last for the next few hundred years.
His most interesting type of minerals oceans - is the famous iron-manganese concretions, which are covered by vast plains of the area underwater. The nodules are a kind of a cocktail of Metals: there include copper, cobalt, nickel, titanium, vanadium, but, of course, most of iron and manganese. Their locations are well known, but the results of industrial development is still very modest. But the full swing of ocean exploration and production of oil and gas in the coastal shelf, the share of offshore production is approaching one third of world production of these fuels.
In a large scale is the development of oil fields in the Persian, Venezuela, the Gulf of Mexico, the North Sea, oil platforms off the California coast stretch, Indonesia, in the Mediterranean and Caspian seas. The Gulf of Mexico also known open during oil exploration mine sulfur, which drips out from the bottom with hot water. Another, as yet unspoiled ocean pantry are deep crevices, where it forms a new bottom. For example, the hot (60 ° C) and heavy brines Red sea basin contain huge reserves of silver, tin, copper, iron and other metals.
More and more important mining takes materials in shallow water. Around Japan, for example, is sucked through the pipes underwater iron sands, the country produces from offshore mines about 20% of coal - over deposits of rock construct an artificial island and a drill stem, chiseling coal seams.
Many natural processes occurring in the oceans - the movement, temperature of water - are inexhaustible energy resources. For example, the total power of the ocean tidal energy is estimated from 1 to 6,000,000,000 kWh. This property tides already used in France in the Middle Ages: the XII century mills were built, the wheels are set in motion a tidal wave.
Today in France, there are modern power stations using the same principle: the rotation of turbines at high tide occurs in one direction, and at low tide - in another.
11. The Living Planet - The Open Ocean
This programme concentrates on the marine environment. Attenborough goes underwater himself to observe the ocean's life forms and comment on them at first hand. He states that those that live on the sea bed are even more varied than land inhabitants. Much sea life is microscopic, and such creatures make up part of the marine plankton. Some animals are filter feeders and examples include the manta ray, the basking shark and the largest, the whale shark. Bony fish with their swim bladders and manoeuvrable fins dominate the seas, and the tuna is hailed as the fastest hunter, but the superiority of these types of fish did not go unchallenged: mammals are also an important component of ocean life. Killer Whales, dolphins, narwhals and Humpback Whales are shown, as well as a school of beluga whales, which congregate annually in a bay in the Canadian Arctic — for reasons unknown. Marine habitats can be just as diverse as those on dry land. Attenborough surmises that the coral reef, with its richness of life, is the water equivalent of the jungle. Where the breezes of the Gulf Stream meet those of the Arctic, the resulting currents churn up nutrients, which lead to vegetation, the fish that eat it, and others that eat them. Attenborough remarks that it is man who has been most responsible for changing ocean environments by fishing relentlessly, but in doing so has also created new ones for himself — and this leads to the final episode.
