In our days, 70, 8% of the surface of the planet is covered by water and, of these, the majority corresponds to the seas. the importance that the aquatic environment the hydrosphere on earth becomes even more evident if we consider that the average height of all the emerged lands is 875m above sea level, while the average depth of this is 3,800m.
also the highest mountain on the planet, the everest, with its 8,848m, would fit perfectly in any of the pits or marine chasms, which sink to 11,000 m depth.
physical and chemical processes that contribute to modify the face of the planet take place in this huge mass of water. currents, waves, erosion, dissolutions, materials, cyclones, ice, etc., are some of the elements more or less directly linked to the marine environment that confer this special characteristics.