Why is Ocean Water Salty?

Why is Ocean Water Salty? Over 75% of the earth’s surface is covered with water in the form of Oceans, seas, lakes, rivers, and other water bodies. Out of this, over 97% of the water is salty and undrinkable. According to scientific sources, 35 parts of salt is present per 1000 parts of ocean water. Though it might make water undrinkable for humans, it is a life-preserving substance for millions of species that live in the ocean.

In this article, we have provided the Salinity of Ocean water, and will give answer to the question – Why is Ocean Water Salty?

The Saline Composition

The Ocean water consists mainly of chloride, Sodium, Magnesium, and Sulphate ions. Several other salts are also present in minor concentrations. The presence of all these ions makes the Ocean water salty.

Why is Ocean Water Salty?

The salty nature of the Ocean water is due to two major reasons:

1. Erosion of Rocks
2. Openings on the ocean floor

1. Erosion of Rocks Causes the Ocean Water Salty

One of the steps in the flow of the water cycle is condensation of clouds and falling of water on earth in the form of rains. When the water falls on the earth, it absorbs the atmospheric Carbon Dioxide (CO2). Due to this, the water turns slightly acidic in nature. This acidic rain water causes erosion of rocks and the salts such as Sodium (Na), Chlorine (Cl), present in the rocks, get mixed in the rain water. Now, this rainwater along with the dissolved salts flows through the rivers and eventually gets into the seas and the Oceans. This is called as ‘runoff from land’.

2. Openings in the Sea Floor Make the Ocean Water Saltier

The Ocean water gradually seeps below the cracks in the ocean floor, where it starts getting heated by magma of the earths core. This heating causes a chain of chemical reactions. As a result, the water loses ions such as magnesium (Mg), Sulphate (SO4), Oxygen (O2) and acquires other ions such as Iron, Zinc, and Copper from the rocks surrounding the magma.

This heated water eventually comes back into the ocean through the openings in the ocean Floor, making the ocean saltier.

NOTE: Over 3.5 Percent of Ocean’s weight is just because of salt.

Why is it important for Oceans to be salty?

Oceans are home for millions of species which in one way or the other support our existence on this planet. The current composition of oceans makes it a habitat for these species to live. If the oceans are ripped off its salt, all the animals except the fresh water species, would die due to the process of osmosis. This would result in breaking of multiple food chains and eventually threaten existence of humans on this planet.

Salinity is a critical factor in the functioning of the Earth’s climate system. It affects the density of seawater, which, in turn, influences ocean circulation and the distribution of heat around the planet. Understanding ocean salinity is essential for predicting and monitoring climate changes and their impact on weather patterns and sea-level rise.

The salinity of ocean water is a result of complex interactions between geological, environmental, and climatic processes. It’s not solely the result of saltwater, but rather a delicate balance of inputs and outputs that have developed over millions of years. Ocean salinity is a testament to the intricate and interconnected nature of our planet’s systems, and studying it helps scientists gain a deeper understanding of Earth’s environmental processes and its impact on the global climate.

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Summary – Why is Ocean Water Salty?

Ocean water is salty mainly because of two big reasons: the first is erosion of rocks and the second is openings in the sea floor. When it rains, the water grabs carbon dioxide from the air, making it a bit acidic. This acidic rainwater breaks down rocks, picking up salt and minerals, and carries them to the ocean. Also, water goes into cracks in the ocean floor, heats up, reacts with rocks down there, and brings even more salt up when it comes back out. This whole process makes the ocean salty, which is super important for all the creatures living there. If the ocean wasn’t salty, many sea animals would not survive, and that would be bad news for us too since we’re all connected in the big circle of life. Plus, the saltiness helps our planet in ways like affecting the weather and keeping the Earth’s climate in check. So, next time you taste the salty ocean, remember it’s all part of a huge natural system that keeps our planet alive and kicking.

FAQs on Why is Ocean Water Salty?

What causes rain water to turn acidic?

In addition to Carbon Dioxide, other gases such as Sulphure Dioxide and Nitrgen Oxides, if present, also react with water turning the rain water more and more acidic.

Why aren’t other water bodies salty?

Other water bodies such as rivers, streams and lakes also have some amounts of salt mixed in them. But the constitution of salt is so less that it doesn’t make it undrinkable. Also these water bodies are continuously flowing, so the salt doesn’t deposit in one place.

Why doesn’t evaporation of water from oceans make it less salty?

When water gets evaporated from the oceans, it leaves behind the salt in the ocean itself. Thus salt keeps getting accumulated over time making it more and more salty.

What if seas and oceans were not salty?

As 3.5% of ocean’s weight is salt, over forty quadrillion tonnes of salt must have to be removed to make seas and oceans free from salt. This significant reduction in weight will trigger earthquakes, Tsunamis, volcanic eruptions all over the world. Apart from this, millions of species which live in seas and oceans would die of osmosis bringing disruption in the food web.

Why can we easily float on water bodies like the dead sea?

Water bodies like dead sea, consists of very high concentrations of salt in comparision to normal sea water. This increases the density of water. Now, our bodies become less dense w.r.t the dead sea water and as a result we can float.