Why is the ocean salty?

Let's dive into a big, blue mystery. Why is the ocean salty? Imagine we're on a great adventure, moving through the waves, feeling the splash and the sun. Let's find out together and have some fun.

Long, long ago, before you and I, before the dinosaurs, even before the first trees grew tall, there was water. But this water was not like the ocean we know now. You see, the rain that fell on the young, rocky Earth began the tale. Rain is like nature's bath; it washes the rocks. When the rain kissed the Earth, it hugged the rocks and took tiny bits of salt with it on a journey to the sea.

The rivers are like roads for water. They carry rainwater from the land to the ocean. And like kids picking flowers or stones on a walk, these rivers pick up a little salt from the rocks and soil they pass by. They don't even know they're doing it. Every river is doing this, all around the world, even now, while we talk.

Now, imagine a very, very big number. Every day, rivers carry four billion tons—that's like the weight of eight hundred thousand big elephants—of water to the sea. And with all that water, even a pinch of salt from each river adds up. It's all going into the ocean, making it a salty soup.

But hey, salt doesn't just come from the land. Down below, in the ocean's deep floors, there are cracks. These aren't scary cracks; they're more like the vents in your house, where warm air comes out. Through these sea-floor vents, salt comes out too. It's a different kind of salt from the rock wash we talked about. It's like the Earth's own recipe, mixing things up from deep down, where it's very, very hot.

That's not all, there are other big words, like 'evaporation,' but think of it as the sun helping the water dance into the sky, leaving the salt behind. Like when you're playing with water on a hot day. If you dry up, your skin might feel a little salty. It's the same with the ocean.

Let us not forget, the ocean has been around for a long, long time. Like a big bathtub that’s being filled drop by drop, over four billion years or so. And no one pulls the plug. The water leaves by floating into the sky, but the salt stays in the tub. Over these huge, big years, tiny bits of salt became the big, salty ocean we can dip our toes in.

Fish and other ocean critters think the salt is just fine. They're built for it, like how a snowman is built for cold and wouldn't like a warm, sunny beach. And plants in the ocean, like seaweed, are like the cactus in the desert. They don't mind the salty water; it's their home.

So, why is the sea salty? It's the rain washing rocks, it's the rivers on their slow walks, it's the vents on the sea floor, and the sun playing its part.

Now, make believe you're an explorer. You have a big, white boat and a map. You're sailing on the salty sea looking for a treasure. With each wave, you're riding on the work of thousands of years, and you're part of the story now.

But remember, we must be gentle with our big, salty ocean. It's the only one we have. It gives homes to fish and whales and tiny things we can barely see. And it's our turn to look after it, to keep the water clean, and to tell others why it's salty, spreading the tale like the whispering wind over the waves.

Tonight, when you round up your toys and put them to their nightly rest, think of the ocean as a great big bed where all the salty water lays down too. And dream of all the rivers still walking to the sea, carrying whispers of the old rocks, making sure the ocean stays salty for you and me.

So now, our big, blue mystery isn't so mysterious anymore. And the next time you taste the salty sea, you'll know the secrets it's held for so much more than a day, so much more than a year, longer than all the tall tales and the trees and the dinosaurs. It's a part of our planet, a salty drop in the great big universe. And isn't that just the most exciting story to be a part of?