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Further Investigations: Density, Temperature, and Salinity


Fig. 2.7. Create water layers by pouring water of a different temperature or salinity slowly down a stirring rod.

Image by Byron Inouye

  1. Simulate layers of water formed by differences in temperature and salinity.

  1. Prepare two 100 mL water samples, one of cold salt water and the other of warm fresh water. Add a different color of food coloring to each.

  2. Place the cold salt water into a beaker. To prevent mixing, slowly pour about 20 mL of the warm fresh water down a stirring rod or down the back of a spoon onto the cold salt water in the beaker (Fig. 2.7). Look for evidence of layering.

  3. Test different combinations of water temperature and salinity.

  4. Try to create three or more water layers in your beaker.

2. What do you think the relative density of the bag alone (empty of liquid) is in the Density Bags Activity? How might the density of the bag affect the results? Design an experiment to test your hypothesis.

Exploring Our Fluid Earth, a product of the Curriculum Research & Development Group (CRDG), College of Education. University of Hawaii, 2011. This document may be freely reproduced and distributed for non-profit educational purposes.