Thermal currents.
Grade Level/Subject: Second Grade Science
Journal by Dale Hegler
During our fifth class we continued our discussion of planning an ocean crossing and preparations for a voyage. After sharing ways we are incorporating course topics in our classrooms we discussed factors that favor a successful voyage.
Then the class was divided into groups to chart a Trans ocean course, decide about supplies, clothes, and food to take. Neal gave each group an assigned number of people making the trip and a variable they will have to contend with (as bad weather or a repair that will be necessary).
For my second graders I wanted to show how unstable air masses or water of different temperatures can be. For our class of teachers as well as my second graders I demonstrated first with a container of hot water dyed red inverted on top of a like container of cold water dyed blue. A cardboard square was across the openings. When the square was removed the red water remained on top and the blue on the bottom indicating a stable system. However, when the demonstration was done in reverse (hot on bottom and cold on top), and the cardboard was removed, there was a dramatic rush of water. Immediately the water turned purple as the hot rushed up and the cold moved down indicating a very unstable system. The second graders colored this on their activity sheet and wrote a conclusion statement.