The hydrosphere consists of all the water on the Earth, in all of its states, on and beneath its surface and in its atmosphere. About 97% of the water on Earth consists of salt water from oceans and seas. Saltwater covers 70% of the Earth’s surface. Visit http://earthfacts.com/ to learn more facts about the earth and you may also like our Facebook Page – https://www.facebook.com/Earthfacts.com. Marcia Malory is a Freelance Science writer from York, England.