Ocean salt primarily comes from rocks on land and openings in the seafloor. Salt in the ocean comes from two sources: runoff from the land and openings in the seafloor. Rocks on land are the major source of salts dissolved in seawater. Rainwater that falls on land is slightly acidic, so it erodes rocks.
One of the most well-known techniques used to obtain safe drinking water is through distillation. You can safely drink the salt-free water vapor collected when you boil seawater.
A litre of seawater contains around 35g of dissolved salt, so desalinating the entire ocean would involve removing 45 million billion tonnes of salt. The sudden reduction in weight pressing on the seabed would probably trigger earthquakes and volcanoes around the globe.
All salt is sodium chloride, and it all comes from the sea.
Yes, you read that right. All salt is sodium chloride (NaCl), and it all comes from seawater — even table salt.
In a new study, Yale professor of Earth & planetary sciences Jun Korenaga and graduate student Meng Guo suggest that for the first 500 million years of Earth's existence, its oceans may have contained a salt level as high as 7.5%. Today's oceans, by comparison, are about 2.5% salt.
Early human hunters obtained their salt from eating animal meat. As they turned to agriculture and the diet changed, they found that salt (maybe as sea water) gave vegetables the same salty flavour they were accustomed to with meat.
In the beginning, the primeval seas were probably only slightly salty. But over time, as rain fell to the Earth and ran over the land, breaking up rocks and transporting their minerals to the ocean, the ocean has become saltier. Rain replenishes freshwater in rivers and streams, so they don't taste salty.
Humans, like other mammals, relied on the small amounts of salt naturally present in food to regulate the amount of fluid in the body. Very powerful mechanisms for conserving salt within the body were developed. The addition of salt to food began relatively recently, about 5000 years ago.
As the human diet moved away from salt-rich game to grains, more salt was needed. Surface salt is relatively rare and mining was difficult – and so, as civilisation spread, it became a precious commodity and trading routes were established all around the world.
China is the world leader in terms of salt production, with 64 million metric tons of salt produced in 2022.
While our planet as a whole may never run out of water, it's important to remember that clean freshwater is not always available where and when humans need it. In fact, half of the world's freshwater can be found in only six countries. More than a billion people live without enough safe, clean water.
Under pressure
One of the biggest challenges of ocean exploration comes down to physics. Dr. Gene Carl Feldman, an oceanographer at NASA's Goddard Space Flight Center, explains that the ocean, at great depths, is characterized by zero visibility, extremely cold temperatures, and crushing amounts of pressure.
If you drank seawater, the salt would get absorbed into your blood along with the water . That would make your blood too salty. So, your kidneys would have to remove the salt. But to do that they would need to use even more water!
Avoid using rainwater for drinking, cooking, brushing your teeth, or rinsing or watering plants that you intend to eat. Instead, use municipal tap water if it is available, or purchase bottled water for these purposes.
Drinking seawater can be deadly to humans.
While humans can safely ingest small amounts of salt, the salt content in seawater is much higher than what can be processed by the human body.
The least saline ocean, by comparison, is the Arctic Ocean, which has a typical salinity of 28–30 g/kg owing to the low rate of evaporation and meltwater from the ice-caps.
[1]It might seem hard to believe today, but salt was once worth its weight in gold, and the balance between these two precious resources determined life for hundreds of thousands in medieval African civilizations.
This basically means, that the reason you have been hearing about salt being more valuable than gold, all this time, is wrong. The fact is that it was actually salt trade that held more worth than the gold industry. Check out the video elaborating the fact!
Salt was a plentiful mineral that ancient civilizations easily obtained by evaporating seawater and certain types of spring water, or from bountiful salt mines. Conversely, gold was exceedingly rare and required great effort to find, mine, and refine.
In severe cases, low sodium levels in the body can lead to muscle cramps, nausea, vomiting and dizziness. Eventually, lack of salt can lead to shock, coma and death. Severe salt loss is very unlikely to happen because our diets contain more than enough salt.
They ate a lot of meat, and the salt content of meat is pretty-much identical to human salt needs.
Early hunters could get a steady supply of salt from meat, but agricultural groups had to seek it out by following animal tracks to salt deposits.
– Yes. The water on our Earth today is the same water that's been here for nearly 5 billion years. Only a tiny bit of it has escaped out into space.
97% of the earth's water is found in the oceans (too salty for drinking, growing crops, and most industrial uses except cooling).
The answer is that the rain does indeed come from the ocean. But as the seawater evaporates under the hot tropical sun, and moves up into the atmosphere as water vapor, it leaves its salts behind. It's just like distilling water by boiling it, capturing the steam and condensing it again as a liquid.