The Origin of Ocean Salt

The saltiness of the ocean comes primarily from rocks on land. When rain falls, it slightly absorbs carbon dioxide from the atmosphere, forming a weak carbonic acid. As this rainwater flows over rocks, it slowly erodes them, dissolving minerals especially salts like sodium and chloride. These minerals are carried by rivers into the oceans, where they accumulate over millions of years. While rivers themselves are not very salty, the continuous flow of mineral-rich water into the seas gradually increased ocean salinity to its current level.

A Delicate Balance in Nature

Despite this ongoing process, the ocean doesn't keep getting saltier forever. A natural balance exists where some salts are removed from seawater by various biological and geological processes. Marine organisms use certain minerals to build shells and skeletons, while others get trapped in ocean sediments. Still, the average salinity of seawater has remained relatively stable over time about 3.5%. This balance is crucial, as the salinity affects ocean currents, marine life, and even global climate. Without this salty consistency, life in the sea and on Earth would look very different. Shutdown123