Book 6, Question 1
Why Is the Ocean Salty?
Rain slowly wears tiny bits of salt and other minerals out of rocks. Rivers carry those bits to the sea. Then the sun lifts the water away, but the salt stays behind.
From the book
Page from A Million Whys Book 6
More fun facts
- Ocean salt comes mostly from rocks on land and from openings in the seafloor.
- Rain wears down rocks on land, and rivers carry their minerals to the sea.
- The ocean collects the salt and minerals from all the rivers that flow into it.
- At hot vents on the seafloor, seawater soaks into rock, heats up and dissolves minerals.
- Salinity is the amount of salt dissolved in water.
- NASA's Aquarius mission, launched on June 10, 2011, mapped how salty the sea surface is around the world.
Sources: NOAA Ocean Service, NOAA Ocean Service, U.S. Geological Survey, NASA Science
Questions kids ask
Why aren't rivers salty like the ocean?
Rivers keep flowing, but the ocean collects the salt from all the rivers that pour into it.