Challenge: Ocean layers in a cup


First watch this video to gain some perspective of how deep the ocean really is. Then click this link to learn about the mariana trench (which is the deepest point in the ocean.) Now that you have gained some knowledge about the size of the ocean and the deeper parts of the ocean, we can learn about how deeper water is denser, colder and saltier while the shallower water has a lower salt content and is warmer. Next we’ll do an activity! First, grab a mason jar that can hold about 3 cups of water. Next, dissolve 3 tablespoons of salt and 2 drops of blue food coloring into one cup of hot water and stir until dissolved, let it cool and pour into the mason jar. Then dissolve 1 tablespoon of salt into a cup of hot water, add 1 drop of blue food coloring and let it cool. As a finishing step very carefully pour the lighter blue water into the mason jar being careful not to disturb the first layer of water. When you’re done you should have a jar with two separate layers demonstrating how water with a higher, denser salt content will sink to the bottom and the less salty water will rise. This small scale experiment is exactly what happens in the larger scale ocean. When you’re finished send a picture to so I can see your creation!

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