|
|
The total surface of the seas is 361.3 million km, which accounts for 70.8% of the surface of the sphere. The total volume of water is 1338.5 million cubic kilometers, that is to say 93.9% of the hydrosphere, i.e. all water of the sphere. The average depth of the seas and oceans is 3711 m, it reaches to the 11034m maximum in the pit of Mariannes. The salinity of sea waters varies (according to Defant, 1961) from 3 to 38 G of saltper kg of sea water, on average it is 3,5 %. The ice-barrier covers has the end of the summer 11.2 million km, at the end of the winter it covers 38 million km2 is 7% of the sphere and 12% of the seas The weight of the sea in the world economy is very significant. The leisures have a weight of 100 billion francs, the food resources of 105 billion francs, the oil of 200 billion, the ores of 5 with l0 billion. On the whole, one counts 200 million alive men of the sea.
|
|
Copyright - manon.org - 02/01/2000 -
|
