How Does Fresh Water Meets Sea Water – Boundary Explained Work?

Fresh water meets sea water at a boundary, just like when you pour juice into a glass of soda, they don’t mix right away.

Imagine you're playing with two buckets: one has clear, fresh water (like the water from your tap), and the other is salty sea water (like the ocean). When you pour them together, they don’t all blend in an instant. Instead, there's a line where they meet, that’s the boundary.

Fresh water is lighter than sea water because it doesn’t have as much salt. So, when they come together, the fresh water floats on top of the salty water for a little while, like oil floating on water in a kitchen sink. This makes a visible layer, or boundary, between them.

Over time, the two waters start mixing, just like how your juice and soda will eventually become one color if you leave it alone. But at first, there’s that fun little boundary where they meet!