What makes the sea salty?

HAVE you wondered what gives the sea its signature saltiness?

Salts come out of rocks, often thanks to the rain. Rain is slightly more acidic than pure water, because carbon dioxide from the air combines with water to form carbonic acid. In most cases, rain is not acidic enough to harm plants or animals – although certain pollutants from factories and cars can make what’s called acid rain, which can cause all sorts of problems. But rain does cause rocks to erode, or slowly break down over time. Minerals, including various salts, break free from rocks and seep into the ground or water around them.

When the planet was new, our oceans probably weren’t that salty. Their saltiness – called salinity – built up over time. The National Oceanic and Atmospheric Administration estimates that if you took all the salt out of the ocean and spread it out on land, it would form a layer 152m thick.

The ocean isn’t the only place that accumulates salty water. The Dead Sea – which is bordered by Jordan, Israel and the Palestinian territories, and considered one of the saltiest bodies of water on the planet – is actually a lake.

Although seawater is fun to play in, try your best not to swallow more than an accidental mouthful. Your body needs salt to survive, but you must urinate any extra amount before it poisons you. – Washintgon Post

PICTURE: OUPA MOKOENA/AFRICAN NEWS AGENCY (ANA) during the environmental fun day at the Waste Group in Pretoria.

Seawater is so salty that gulping large amounts will make you dehydrated. PICTURE: WASHINGTON POST