Why is Ocean water salty?

Why is Ocean water salty?

Why is Ocean water salty? The world is surrounded by water. In fact, ocean covers 70% of the Earth’s surface and account for about 97 percent of all water. And approximately around three and a half percent of total ocean water is salt, which may not sound like too much, but in works out to 120 million tons of salt per cubic mile of seawater. Where did all the salts come from?

Salt in the ocean, comes from mainly 2 sources, run-off from the land and openings in the seafloor. When the rain forms and pours through the air, it collects carbon dioxide from the atmosphere on its way, turning the freshwater slightly acidic in nature. And once this acidic water meets the land’s surface, it erodes the rocks and picks up small amounts of salt and other dissolved minerals already present in the rocks. At this point, the water is still basically fresh there is some salt in it but usually not enough to make it undrinkable.

But when this mixed rainwater makes its way to the ocean. Over there, some of the dissolved minerals, such as calcium, are extracted from the water by the organisms through a biological process, but salt tends to remains. Thus, making the water undrinkable and salty. But not only that, another factor responsible for turning the oceanic water salty is hydrothermal fluids which comes from the vents in the seafloor. When salted ocean water seeps into cracks in the seafloor, over there, it gets heated by magma from the Earth’s core.

This heat causes a chain of chemical reactions and the water tends to lose the oxygen, magnesium and sulfates and pick up metals such as iron, zinc and copper from surrounding rocks. The heated water is released through the vents in the seafloor, carrying the additional metals with it, and as a result, the ocean water gets saltier.

Why aren’t lakes and rivers salty? These water bodies have some amount of salt in them too but as they are continually flowing, it’s hard for the salt to get accumulated and gets carried away into the ocean, rubbing more salt into its wound.

But remember, this salted water is home to many aquatic animals and plants and plays a massive role in the existence of our Earth. So we need to make sure to keep our oceans clean and free from any pollution.

Did you know, two of the most common minerals in seawater are called chloride and sodium? Together, they make up around 85% of all dissolved minerals in the ocean.