Three quarters of the surface of the Earth is covered by ocean. The ocean is given five names, or there are five "oceans" as follows:
One of the most dramatic forms of weather occur on the oceans: hurricanes, which are known as typhoons in the Pacific Ocean. Ocean currents greatly affect the earth's weather--for example, El Nino and La Nina in the southern Pacific Ocean greatly affect the weather of The Americas.
The study of the earth's oceans is called oceanography.