Why is the ocean salty
All rain water on the earth, including fresh water and rain water contains dissolved solids that scientists refer to as “salts”. The concentration of these salts differs depending on the water body but the ocean is typically regarded as one of the saltiest bodies of water (barring of course, the Dead Sea).
Oceans naturally break up the minerals within them through natural wear and tear from ocean currents, storms and general movement. The Ocean is a massive weight and a powerful force which results in the ocean floor, beaches and other debris being slowly broken down and dissolved. In fact, sand is formed because the ocean tide repeatedly wears the rocks down until they are fine grains. This process has been going on for many, many years and the amount of minerals in ocean dissolved has become somewhat staggering.
While all water has some natural level of salt within it, when this concentration becomes too high our taste buds reject the water as it is unfit for human consumption. To put this into perspective we have no problems drinking tap water which naturally contains some dissolved minerals. When we add a slight pinch of salt to this water most of use will still be able to drink this water without too much trouble. When we then add a whole teaspoon of salt to a glass of water, the taste becomes unbearable and the drink is ruined. This level of salt to water ratio is similar to that which can be found in the sea.
Scientists have varying views on the estimated level of salt in the Ocean today however most have concluded the Ocean holds approximately 50 quadrillion tonnes of salt (dissolved solids). For many of us, that is a wholly unimaginable number. One popular perspective to show you how salty the ocean is to imagine the entire Ocean’s salt was collected together in a sold mass and spread out over the earth. This layer would be around 500 feet thick which is about as tall as a 40 story office building.
Ocean water is comprised of a very complex solution of various different mineral salts that have collected up over time as well as some decayed biological matter. Most of these ocean salts were created from long and arduous processes such as weathering, erosion and cooled igneous rocks being broken down over time. Rains and streams that flow into the ocean also contribute to this as their strong currents transport extra minerals from the mountains through to the bottom of the sea.
Despite a few fresh rivers pouring into the seas and the ocean this does not make the ocean any fresher. This is because these rivers are only a small fraction of what makes up the ocean and many rivers actually server to transport extra minerals down into the ocean depths. It has been suggested that in the very beginning the ocean must have been very fresh. However, ever since the first rains that spread over the earth and washed the minerals into the ocean these water have become saltier and saltier.