Billions of years ago planet Earth did not look like it does today, it was covered in lava and volcanoes. There was no possible way that life could exist on the planet. However, eventually the planet started cooling down; huge amounts of steam rose causing clouds. Then the clouds rained. One thousand years of continuous raining caused oceans which made earth like it is today. Planet Earth, also known as the blue planet, has oceans covering three quarters of the Earth’s surface.
Oceans have a system to try and keep the water temperatures even, whether or not the climate is the same. This is called the ‘Thermohaline Conveyer’. This is when water from the Tropics (warm water) is pushed towards the Poles where there is cold water and that water is then pushed into the tropics. This is a constant cycle. This cycle plays an important role in supplying heat to the the Poles. When warm water travels to the Poles, it mixes with the Antarctic water. This water then becomes so dense that it sinks, only to rise again as it warms. However, if temperatures rise and water in the Polar regions no longer sinks, the whole system can collapse. This has happened long, long ago.
Having a huge effect on life on Earth, Oceans important role to play. Phytoplankton (tiny organisms in the sea), are at the bottom of the food chain and if they died out this would cause extinction of loads of other sea creatures as well. These also photosynthesize ( turn co2 and sunlight into energy) and release oxygen. Due to the incredibly large number of these species they produce around 50% of the world’s oxygen. Also some land animals are dependent on the sea as drinking and fishing grounds.
Occasionally around the Equator an ‘El Nino’ happens. Usually this is caused by strong winds moving from East to West along the Equator. This actually piles up water in the western side of the Pacific. In the eastern part the deeper water, which is far colder than that on the surface (which is warmed by...
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