Why Is Sea Water Salty/Saline?

If you’ve ever taken a gulp of seawater, either accidentally or in a moment of insanity, then you undoubtedly noticed that seawater is actually very salty. If you haven’t tasted it yet, why not give it a try? We do have plenty of oceans around the world!

A Salty Reason

Contrary to popular belief, freshwater, which is the water we drink, also contains some amount of salt. However, because the concentration of salt is much less than seawater, this salinity isn’t apparent in the taste of the water. There are 2 theories attributed to the salinity of seawater. One is that when rainwater seeps through large rocks, it mixes with some of the minerals from the rocks, a process that is called weathering.

This water, which has taken in some of the salty substances of the rocks, then flows through rivers, making the water in the river slightly salty too. That being said, you won’t find the river water salty, as the concentration of salt in that water is also quite low. The water from all rivers is deposited in the seas and along with it, the salt also gets deposited, making the seawater salty. This exact same process has been going on for millions of years, which has made the salinity of seawater become apparent to our senses.

The other reason that is commonly attributed to the salinity of seawater was discovered a number of years ago. There are some areas on the ocean floor where seawater seeps into the oceanic crust, becomes hotter, dissolves minerals from the crust, and then flows back to the ocean. Again, this process takes a long, long time, but it can definitely contribute to salinity.

Furthermore, it has been found that underwater volcanic eruptions also impart salinity to seawater. As you can see, there are plenty of popular explanations, but the bottom line is this – don’t take a gulp when you’re thirsty, because it will only make things worse!


  1. The University of Texas at Dallas
  2. National Oceanic & Atmospheric Administration
  3. Victor M. Ponce – San Diego State University
The short URL of the present article is: http://sciabc.us/sR9Dt
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