|
Oceans and Water
Factfile |
 Oceans and Water |
 |
Introduction |
|
Waterfall - Steve Canipe
As one of Earth’s most important features, we often take water for granted. Without it everything would die, as all life on Earth needs water. Water is also an important feature in our weather as without water there would be no clouds, snow, rain and hail.
The world’s oceans cover nearly three-quarters of Earth’s surface, to an average depth of 3.8 m. Ocean water is constantly moving as it moves around the planet in well-defined circular patterns called currents. These currents flow like rivers, carrying warm water from the tropics and cold water from the Poles.
A mass of water can store more heat from the Sun than the same mass of air can. Where the two currents meet at the equator, the colder water sinks, pushing warmer water up to the surface as a surface current. These warm surface currents then heat the air above them and if the air then moves over land, it warms the local climate. The warm water then flows towards the poles, where it cools and sinks and has the effect of cooling the air and the local climate before beginning to flow back towards the equator again.
Without currents, the Earth's temperatures would change dramatically. The Equator would get much hotter, while the North and South Pole would get even colder, so water is essential for the world’s weather and climates.
On the surface of the ocean, the wind blows the water into waves and waves help to churn up the water, spreading nutrients and oxygen for animals and plants to the deepest parts of the ocean. This process is also helped by the regular movement of tides. Twice a day, all over the world, oceans rise and fall along the coastline, with waves that stir up the water, producing bubbles of oxygen which sea creatures need to breathe.
While the world’s oceans may appear empty and unchanging, beneath the surface hides a unique world where water takes the place of air in an incredible landscape of mountains, trenches, volcanoes and plains. Thousands of plants and animals live in this amazing environment and when we have discovered the means to explore its depths, it is likely that many more ocean species will be found.
|
|
|
|
|
|
|
|
