If you’ve ever wondered why the sea tastes salty, the answer comes down to billions of years of water doing the slow work of dissolving rocks. Rain falls on land, picks up tiny amounts of minerals from the rocks it flows over, and runs into rivers. Rivers carry the dissolved minerals into the ocean.
Once that water is in the ocean, it doesn’t stay forever. Sunlight evaporates water off the surface, which rises into the sky and eventually falls again as rain - but pure, without the salts. The minerals get left behind.
Repeat that process for about 4 billion years and you build up the ocean we have today. Roughly 3.5% of the ocean’s weight is salt. If you somehow extracted every bit of salt and spread it evenly across the land, you’d cover every continent in a layer roughly 500 feet thick. That’s where it all went.
