Unit 07 · The Hydrosphere (oceans & the water cycle)
Almost all of Earth's water is in one connected system, and this unit follows it. It covers the water cycle in full — evaporation and transpiration, condensation and precipitation, runoff and the groundwater most people forget — and then the ocean that drives it: the currents that move heat around the planet, the waves and tides that shape the coast, and the salinity that sets seawater apart from fresh. Mastery means you can trace a water molecule through every reservoir, not just from the puddle to the cloud and back.
| Criterion | Not yet | Approaching | Mastered |
|---|---|---|---|
| The water cycle (full) | Thinks the water cycle is just evaporation and rain. | Adds condensation but leaves out transpiration, groundwater, or ocean circulation. | Traces water through evaporation, transpiration, precipitation, runoff, and groundwater, and back to the ocean. |
| Ocean currents | Sees ocean currents as random or unrelated to climate. | Names currents but cannot say what drives them or what they move. | Explains how wind, density, and Earth's rotation drive currents that redistribute heat around the globe. |
| Waves, tides & salinity | Confuses waves with currents or thinks tides are caused by wind. | Links tides to the Moon in general but not to its position, or treats salinity as fixed. | Relates tides to the Moon and Sun, distinguishes waves from currents, and explains what sets ocean salinity. |
| The ocean as a system | Treats the ocean as a still reservoir disconnected from weather and land. | Links the ocean to weather loosely but cannot connect currents, evaporation, and climate. | Connects ocean circulation, the water cycle, and climate into one moving system. |
| Lab technique (current / water-cycle modeling) | Cannot set up or read a model of a current or the water cycle. | Builds the model but misreads what it demonstrates. | Models an ocean current or the water cycle and defends what the model does and does not show. |
| Integration (cross-domain) | Treats the science as isolated facts; makes no cross-domain connection. | Names a link to history, reading, or writing but cannot defend why it matters. | Connects the unit to its anchor across History · Reading · Writing (plus chosen electives) and defends why the connection matters. |
“Explorers who learned the trade winds and the Gulf Stream could cross an ocean and come back — they were reading the currents before anyone could explain them. The same water cycle they sailed through moves heat from the tropics to the poles, and most of the fresh water isn’t in the rivers you can see; it’s groundwater underfoot.”
“The water cycle is water evaporating and then raining back down. The ocean just sits there — it’s separate from all that.”
You demonstrate this unit through ocean-current and water-cycle modeling plus short oral checks where you trace the water through the system aloud, not a multiple-choice test. A criterion counts as mastered only when you can both build the model and justify the circulation behind it. Mastery is demonstrated, not awarded.
A 5-page clipboard packet — unit overview, key terms, the mastery rubric, anchor examples, and a score sheet you can print and grade against.