I don’t know about you but i’ve always wondered that: why is the sea salty? Well, because i’m sure a lot of you useless info junkies out there have also been wondering that, here’s how it goes.
As it turns out, the salt in the seas and oceans comes from rocks on land.
The rain that falls on the land contains dissolved carbon dioxide which comes from the surrounding air. This causes the rain to be slightly acidic. Therefore when it rains, some parts of the rocks are eroded and break down due to the acid rain. This process creates ions that are carried away in runoff to streams and rivers and, ultimately, end up to the seas and oceans.Two of the most prevalant ions in seawater are chloride and sodium. Together, they make up more than 90% of all dissolved ions in the ocean. Both of them are ‘salty’, hence the sea is salty! So, how much salt there is in seawater? (the article continues after the ad)
About 3.5% of the weight of seawater comes from the dissolved salts. Theoretically, if all the salt in the oceans could be removed and spread evenly over the Earth’s surface, it would form a layer about the height of a 40-story office building.