Essay On Salinity And Minerals In The Oceans

All the world’s oceans are salty; i.e. the water contains much more salt than what we call fresh water, although even that does contain various salts and other minerals, but in relatively tiny quantities. So just how much more salty is that ocean water? To give an example, if a cubic metre of averagely salty seawater was evaporated, it would leave behind about 2.2 pounds (1kg) of salt. If the same were done with a cubic metre of fresh water, it would provide only one hundredth part of a pound of salt (about 1/6th oz.). So sea water is roughly 220 times more salty.
But the saltiness of sea water is not simply suspended “salt” but a complex solution of perhaps 70 or more various mineral salts, believed to have been derived over millions of years from the cooling of the Earth’s surface, from volcanic action and from decaying organic matter. Over many centuries the world’s rivers flowing into the oceans add suspended minerals. For example, taking just the rivers flowing from the U.S., it’s estimated that every year over 700 million tons of solids and sediment flow into the seas around us. As the sun evaporates seawater, it then falls as rain over land and absorbed by plants, etc, so the seawater becomes even saltier.
Actual salinity varies according to ocean location, ranging from 5 parts / per 1000 in the Baltic to 40 parts / per 1000 in the Red Sea, where evaporation is very high, but the average value is 35. I have visited the Mar Menor (small sea) – a semi-landlocked area of the Mediterranean on the Costa Calida (warm coast) in southern Spain, where a recent study measured a value of almost 42. The waters and mud there are known for their healthy qualities.