Why is the sea salty and rivers and lakes aren’t? Also, what’s the difference between sea salt and regular table salt?

The earth’s water goes through a continuous cycle of being evaporated and rained back down. Whenever evaporation happens, water goes up as vapour with essentially no salt in it.

Waterfalls all over the planet, but when it passes through soil and rocks it slowly dissolves bits of minerals, including sodium chloride (salt). This means rivers and lakes have tiny fragments of salt in them, which — little by little — are carried into the sea.

Rivers and lakes are replenished with fresh rainwater, but oceans are a sort of dumping ground where water with accumulated salt keeps adding to the salinity. There are also vents and volcanoes under the ocean that increase the number of minerals, especially salt.

A detailed account of why some elements and compounds are more abundant is a long story, but take it as the fact that of all minerals, sodium chloride is the most common highly soluble one.

This might lead you to worry that the oceans will keep getting saltier with time, but other processes, such as the formation of minerals at the bottom of the ocean, take some salt out.

Sea salt is obtained by evaporating seawater, so it tends to include tiny pieces of whatever else is in the sea, affecting taste and colour.

Table salt is mined from underground deposits but is usually processed to remove impurities and is nearly 98 per cent sodium chloride. Sea salt is about 85 per cent pure (with 15 per cent mainly other minerals).

Iodine is usually added to table salt to help avoid dietary deficiencies, and chemicals like calcium silicate are mixed in to absorb moisture to stop the salt from clumping.

Credits: Nivethitha

Comments

WHY ATLANTIC AND PACIFIC OCEAN ARE NOT MIXED?

Nearly 72% of the earth is filled with water and it is present with different names- oceans, seas, rivers. Why are they named differently? There are five oceans namely Artic ocean, Atlantic Ocean, Pacific Ocean, Indian ocean and Antarctic ocean . All the oceans are different in their physical and biological character called ocean clines. When we look at the Atlantic and Pacific Ocean junction, they do not mix. Is there any invisible Wall in between them? Many scientists have conducted research to solve this mystery. The Atlantic and Pacific Ocean have different chemical composition. The salinity of the water in the Atlantic Ocean is five times more than the Pacific Ocean. The density of water is also different, so even marine animals in Atlantic Ocean will not go to the Pacific Ocean. They cannot survive in other oceans. Atlantic and Pacific Ocean meet at Cape Horn. The narrow straight line formed by the water bodies is called Drake Strait. The Pacific Ocean is ...

The Chemical Lake

Spotted Lake or Lake khiluk in Canada is richly concentrated with various minerals. It contains dense deposits of magnesium sulfate, calcium, and sodium sulfates. It also contains high concentrations of eight other minerals and lower amounts of silver and titanium. Most of the water in the lake evaporates over the summer, revealing colorful mineral deposits. Large ‘spots’ on the lake appear and are colored according to the mineral composition and seasonal amount of precipitation. Magnesium sulfate, which crystallizes in the summer, is a major contributor to spot color. Originally known to the First Nations of the Okanagan Valley (Native American Tribe) as Khiluk, Spotted Lake was for centuries and remains revered as a sacred site thought to provide therapeutic waters. It is the most mineralized lake in the world. Each spot holds a different cure due to the unique chemical content found within each puddle. Lake Khiluk is considered a saline endorheic alkali lake. The Okanag...

Why is the Pacific Ocean shrinking and the Atlantic Ocean is getting wider?

Twenty million years ago there was no Atlantic Ocean. But then, thanks to plate tectonics, the South American and North American continents were separated by a rift valley that eventually turned into the Atlantic Ocean. The complementary shapes of the South American and African continents have long been noticed, but it wasn't until the 1960s that the theory of plate tectonics became accepted as the explanation. These days, the Atlantic Ocean is growing at a rate of five centimetres per year, as new sea floor is created by volcanic activity along its mid-ocean ridge. On the other hand, the much older Pacific Ocean is currently estimated to be shrinking by two to three centimetres each year. Again, this comes down to plate tectonics because the Pacific Ocean has subduction zones on three sides - where the Pacific plate submerges beneath other plates. Since there are very few subduction zones in the Atlantic, Indian and Arctic oceans...

Home

Search This Blog