Oceanography is a science in which we study the characteristics of ocean, sea and other water bodies. According to Proudman, oceanography studies the fundamental principles of dynamics and thermodynamics in relation to the physical and biological properties of sea water. Thus it is a science of sea. Various major oceanic expeditions are responsible for the development of this branch of science.
In the words of Salisbury (Chicago, 1858-1922), the broad features of the earth namely land and sea are the relief of first order, on which the relief of second order plains, plateaus and mountain are formed. The origin of ocean basin has been explained by a number of theories like nebular hypothesis, continental drift, sea floor spreading and plate tectonics.
The hydrosphere covers nearly three-fourths of the earth's surface thus the land and water ratio is 1:2.4. In terms of water and land, the earth's surface can be divided into water and land hemisphere. According to recent measurements the centre of water land hemisphere is on the coast of France at the mouth of Loire and the centre of water hemisphere lies in the Pacific Ocean.
The extent of land and water areas varies between the latitudes. The latitude between 35 o - 65 o N the land amounts to 55.4% of the total area and the equator ward tapering of the continent is predominant.
The land and sea ratio in the northern hemisphere is 1:1.5 and in the southern hemisphere it is 1:4.2. The Atlantic, Indian and the Pacific Ocean dominate the hydrosphere of which the Atlantic Ocean is extensively studied.
"The world is a book, and those who do not travel read only a page", St. Augustine said. Here at www.travel-university.org we believe that every page must be read and explored. Travel is an avenue of learning that no text or classroom can teach. The world is a living classroom and you the student. We invite you to the www.travel-university.org library where you can read general interest and detail oriented articles.
