Here's an Easy, Cheap Demonstration of Deep Ocean Currents
Our 4th grader, "Peel," is studying the oceans in earth science these days, and I like the simple demonstrations her book recommends (it's Harcourt Science). To better understand deep ocean currents--the ones caused by differences in water density and differences in water temperature--we did this simple activity:
1. Freeze an ice cube with food coloring in it the night before you start.
2. Fill a clear bowl with warm tap water.
|We let the water sit still for 10 minutes before carefully lowering our colored ice cube.|
3. We observed what was happening every 2 minutes, for a total of 10 minutes.
Peel drew pictures of each stage in her science journal.
|We began to see a thin blue line of colder, denser water that was sinking.|
4. Connect what you saw with what you know from reading.
|The blue water pooled on the bottom, while the warmer water was displaced.|
National Oceanic and Atmospheric Administration
Watch. Know. Learn.