Book 6, Question 21
Why Is the Ocean Colder than a Puddle?
A puddle is thin and sits in the sun. The ocean is deep, and most of its water never gets a long turn in the heat. Wind and currents also mix cold water upward.
From the book
Page from A Million Whys Book 6
More fun facts
- Cold, salty water is heavy, so it sinks to the bottom while warmer water stays near the top.
- The deep ocean, below about 200 meters, averages only 4 degrees Celsius (39 degrees Fahrenheit).
- The poles get only about 40 percent of the heat from the Sun that the equator gets.
- Deep ocean currents keep replacing the bottom water with even colder water.
- Sinking cold water and wind-driven warm surface water make a giant loop of currents called the global conveyor belt.
Sources: NOAA Ocean Service, NOAA Ocean Exploration, NASA
Questions kids ask
How cold is the deep ocean?
Below about 200 meters, it averages only about 4 degrees Celsius, or 39 degrees Fahrenheit.