UNIT 2: The Earth system
CHAPTER 1
In Chapter 1, students work to answer the question Why is East Ferris running out of water while West Ferris is not? Through reading sections in the Water Encyclopedia about where water exists on Earth and doing a hands-on activity with a globe, students gain an understanding of the distribution of water on Earth. Students read about what can cause a water shortage in Water Shortages, Water Solutions and watch videos that represent water flow into water reservoirs and human consumption from reservoirs. From experience with these sources, students develop an understanding of the substantial cumulative impact people can have on the availability of freshwater. At the end of the chapter, students apply what they have learned about water availability to explain why the groundwater reservoir on Ferris Island is being depleted. They discuss the water shortage as an interaction between the hydrosphere and biosphere.
CHAPTER 2
In Chapter 2, students question why West Ferris can rely on a second water source—rain—while East Ferris has only a diminishing groundwater reservoir. They investigate the question Why does more rain form over West Ferris than East Ferris? Students have multiple opportunities to make sense of condensation and evaporation and how these processes create rain. Through hands-on investigations, observations in The Earth System Simulation, and readings from the Water Encyclopedia, students learn what factors affect condensation and evaporation and what happens at the nanoscale during these processes. Students synthesize ideas from these investigations with ideas from Drinking Cleopatra’s Tears to gain a new understanding of how water is cycled around Earth. Students apply their newfound knowledge to explain why more raindrops form over West Ferris than East Ferris and to discuss how the hydrosphere, atmosphere, and biosphere interact on Ferris Island. Students then use their knowledge of evaporation and condensation to design freshwater collection systems and read Engineering Clean Water to understand the processes by which engineers design solutions. By the end of Chapter 2, students realize that more water vapor must be condensing over West Ferris to create more raindrops, and therefore water vapor must be getting colder on that side of the island.
CHAPTER 3
In Chapter 3, students receive weather reports which show that East Ferris and West Ferris experience the same temperatures, which motivates a new question: Why is more water vapor getting cold over West Ferris than East Ferris? By reading about the atmosphere in Water Encyclopedia, students learn that it is colder higher in the atmosphere. Students build on their understanding of rain by revisiting sections of Drinking Cleopatra’s Tears, observing a model of condensation in the atmosphere, and using The Earth System Simulation to gather information. They figure out that water vapor condenses as it moves higher to where the atmosphere is colder. They use this new understanding to write a more complete explanation of why a lot of rain forms over West Ferris. Students then have an opportunity to iterate on their freshwater collection system designs.
CHAPTER 4
Having established that there must be more water vapor high up over West Ferris for more condensation and rain to occur, Chapter 4 immerses students in figuring out the answer to the question Why is there more water vapor high up over West Ferris than East Ferris? Students use The Earth System Simulation as well as a hands-on investigation of how a mountain and the movement of wind can cause water vapor to move to different areas of the atmosphere. They use what they have learned about the rain shadow effect to explain why West Ferris gets more rain than East Ferris. With information from How the Earth System Explains Dinosaur Extinction, students identify interactions between parts of the Earth system that create the rain shadow on Ferris Island. Students iterate once again on their freshwater collection system designs, applying what they learned from testing their earlier iterations.