The sub can move horizontally, but has lost the engine power to move up or down. The students determine where to find an upward ocean current to help carry them to the surface by experimenting with water at their desks. Groups of four students conduct experiments for two days using cold and hot water with food coloring drops to trace the convection currents in a clear plastic pan. The first day, students concentrate on observation and recording of currents in three experimental trials. Through discussion, students discover a complete convection current and apply this knowledge to guide the imaginary submarine during the last trial on the second day.
Discussion also leads into ocean floor spreading.
The third day, the teacher uses three demonstrations to show convection also happens with gases. Students apply the generalization to problems concerning wind and heating with convection. A Current Event, Alan Gould, Berkeley, CA, 1988. The project has two main strong points. Many students have difficulty understanding this important idea from lecture or readings.