• Question: Why is the sea salty?

    Asked by Ellis to Lisa, Mark, Rachel, Sammie, Stephen, Tim on 7 Mar 2018.
    • Photo: Sammie Buzzard

      Sammie Buzzard answered on 7 Mar 2018:

      When rainwater percolates through soil and rock it dissolves salt and this salty water is carried to the sea in rivers, it took millions of years for the salt in sea water to build up. It was also only discovered in the last 20 years or so that the oceans can dissolve salt from the rocks that make up the earth’s crust below the ocean.

    • Photo: Tim Duckenfield

      Tim Duckenfield answered on 8 Mar 2018:

      Did you know, underneath a lot of the rocks that make up the seabed, there are giant fields of salt hundreds and hundreds of miles big! They formed back in history, when the Earth’s temperature was higher so some of the oceans evaporated. When the liquid went away, the salt was left on the ground. Eventually new rocks formed over this salt, and it got buried miles and miles underground. We often find oil trapped next to this salt, so a lot of people are interested in where they are underground.

Comments