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Student Activity - Water temperature
Activity idea
This activity was adapted from SEREAD in collaboration with NIWA.
The temperature of sea water varies all over the world. The ocean waters near the Arctic and Antarctic will be considerably colder than the water near the Equator.
The temperature of the water affects its density. This in turn affects how the water moves in the ocean, and the way deep ocean currents move.
By the end of this activity, students should understand:
- Cold water sinks below warm water, it is more dense.
- Warm water will sit on top of cold water.
- Wind will mix up the layers of warm and cold water.
Instructions
What you will need
- iced water
- hot water
- 500 ml beaker
- 2 x 30 ml beakers
- red and blue food colouring
- dropper
- red and blue colouring pencils
- straw
Instructions
- Three-quarters fill the 500 ml beaker with tap water and leave to adjust to room temperature.
- Half fill one of the 30 ml beakers with hot water and add some red food colouring.
- Repeat with the other beaker, adding icy water and blue food colouring.
- Gently add a few drops of red hot water to the room temperature water.
- Then add some blue cold water.
- Draw pictures using red and blue colouring pencils to show what happens to the water. You may need to do several pictures over a period of time.
- Hold a straw at the edge of the top of the beaker so that it is parallel to the water surface. Blow gently through the straw.
Thought questions and discussion
- What happens to the water hot and cold water? Do they mix? What would happen when the polar cold water meets the tropic hot water?
- What do you think the density of sea water would be like compared to fresh water?
- What happens to the water when you blow on it?
