Ocean Circulation     The ocean is constantly in motion, distributing water and heat to all corners of the globe. In effect, the ocean acts as a circulating machine that makes Earth’s climate equitable. Ocean currents follow well-defined courses.  Why? Difference in heating leads to the different in surface temperature. This difference causes the movement of water boy (Ocean) that form the current. This method of heat transfer is called as Convection; hence it is sometimes mentioned as convectional currents.  Just like that happens our kitchen while boiling water.     How important it is?   The ocean transports tremendous quantities of seawater, serving as a global conveyor belt over the planet. Abyssal storms stir the deep-ocean floor, shifting sediments on the seabed. El Niño currents generate unusual weather patterns throughout the world. Waves and tides are constantly changing and rearranging the shoreline.       ...

  Chemical properties of sea water & Residence time Chemical properties of sea water: The oceans  cover an area of 361 x 106 km2, or 70.8% of the earth's surface. From the mean depth of 3800 m. the volume of the ocean waters can be calculated to be 1370 x 106 km3. At the surface the density of sea water of normal salinity at 0o C is 1.028, and it increases with depth because of the slight compressibility of water under increased pressure. Seawater thus comprises about 91% of the weight of the hydrosphere and its composition can therefore be taken without serious error as giving an average composition of the hydrosphere. The circulation of the waters in the hydrosphere provides a mechanism for geochemical changes through weathering and transport of dissolved and solid materials.  About 68% of the land area is drained to the Atlantic Ocean but the constancy of ocean composition indicates that seawater mixing erases all (except local) variation in its chemical comp...

  Physical properties of sea water Water makes up more than 96% of the total mass of seawater, so it is appropriate to begin with a short discussion of the properties of water itself. The weather and climate on Earth are in several ways controlled by the physical properties of water. Some of the important properties are,   a. its expansion when freezing,  b. its infrared absorption causes water vapor to be the most important greenhouse gas,  c. its radiative properties cause water to be important in the radiation of heat away from Earth, d. Variations from place to place in its isotopic composition provide insights into several aspects of Earth science, e. The chemical property of water that is perhaps most important to the marine chemist is its high solvent power for polar substances and substances that form charged ions in solution etc.,    Physical properties of water:      The boiling point of water is unusually high. This very hig...

Hypsography of the continents and ocean floor       Hypsometry is the measurement of land elevation (relative to mean sea level). Bathymetry is the underwater equivalent. A hypsometric curve is a histogram or cumulative distribution function of elevations in a geographical area.         Continental margin Continental margin, the submarine edge of the continental crust distinguished by relatively light and isostatically high-floating material in comparison with the adjacent oceanic crust. It is the name for the collective area that encompasses the continental shelf, continental slope, and continental rise. Continental margins are about 28% of the oceanic area. A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water known as a shelf sea. Much of these shelves has been exposed during glacial periods.           The continental shelf (approx 0.1°), steep continental s...