Student Science Journal
6.3.1
Water Cycle
Name ____________________
Episode 1
2
6.3.1
Places Water is Found | Patterns |
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Use the patterns you have observed to categorize and group your locations.
Can you do it with less groups?
3
6.3.1
Write about the patterns of water in Earth’s systems. What are the patterns? How would you explain the earth’s water patterns to someone else?
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Pattern | Location | Explanation |
Example: The majority of freshwater is frozen | Polar ice caps | Most of the earth's freshwater is not in water form, it is ice |
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Episode 2�
4
Define:
Reservoir: ______________________________________________________
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Transfer: ________________________________________________________
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5
Reservoirs | Transfers |
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6
Water's Journey Through Earth's Systems
Have you ever wondered where water goes after it rains or how it ends up in the ocean? Water is always moving through Earth’s systems. It might stay in one place for a long time, or it might be on the move. Scientists call places where water does not move reservoirs, and places where water moves transfers.
A reservoir is a place where water is stored. Think of it like a parking lot for water. Some examples of reservoirs are oceans, lakes, rivers, glaciers, soil, the atmosphere (air), and even underground in spaces between rocks and dirt. Water in a glacier can stay frozen for hundreds or even thousands of years—that’s a very long stay in a reservoir!
A transfer is the movement of water from one place to another. Transfers happen in many ways. For example, when the sun shines, water can evaporate from the ocean into the air. That’s a transfer. When it rains, water moves from the atmosphere to the ground—another transfer! Water can also move as it flows down a river or gets soaked into the ground.
Together, reservoirs and transfers are part of the water cycle. Water moves through this cycle again and again, sometimes staying in one place, and sometimes moving quickly. Even the water in your drinking glass has been through this journey—maybe even many times!
So next time you see a puddle, a stream, or a cloud, think about this: Is the water staying in place as a reservoir, or is it on the move as a transfer?
Episode 3
7
How Water Moves: The Role of Thermal Energy, Density, and Gravity
Water is always on the move—through rivers, into clouds, under the ground, and even inside your body. This constant movement of water is called the water cycle, and it’s powered by some invisible forces: thermal energy, density, and gravity.
Thermal Energy: The Heat That Moves Water
The Sun is the main source of thermal energy (heat) on Earth. When the Sun warms oceans, lakes, or puddles, the water particles gain energy. These fast-moving particles break away from the liquid and rise into the air as water vapor. This is called evaporation. Thermal energy also causes ice to melt into liquid water, while the removal of thermal energy causes water vapor to condense into liquid droplets, forming clouds.
Without thermal energy, water would not change form or move into the air. It’s like the engine that keeps the water cycle running.
Density: Why Some Water Moves Up and Some Sinks
Density is how tightly packed the particles in a substance are. Warm water has less density than cold water, so it rises. Cold water is denser, so it sinks. This difference creates currents in oceans, lakes, and even the air.
When the Sun heats up water at the surface, it becomes less dense and rises. Colder water underneath sinks. This movement helps transfer water and thermal energy across Earth. You can see this happen in a pot of water on the stove or in ocean currents like the Gulf Stream.
Gravity: The Force That Pulls Water Down
Once water vapor rises, cools, condenses and forms clouds, it doesn't stay up forever. Eventually, the drops get heavy and fall as rain, snow, or sleet—this is precipitation. The force that pulls water down from the sky is gravity.
Gravity also causes rivers to flow downhill, groundwater to sink into the soil, and glaciers to move slowly down mountains. After water falls to Earth, gravity keeps it moving through streams, into lakes, and back to the ocean.
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8
Develop a model to explain how energy from the sun (thermal energy), density, and gravitational forces cause the transfer of water from reservoir to reservoir. You should use words and pictures in your model.
(Explanations should describe what is happening at the molecular level and describe the energy and forces causing the transfer.)
Episode 4
9
6.3.1
Questions | Observations |
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What role do living organisms play in the transfer of water?
Write an explanation and draw a picture with labels or add to your model from the previous episode.
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What is transpiration?
The release of water vapor (gas) from plant leaves.
Transpiration has three main steps
How much water do plants transpire?
Plant transpiration is pretty much an invisible process. Since the water is evaporating from the leaf surfaces, you don't just go out and see the leaves "breathing". Just because you can't see the water doesn't mean it is not being put into the air, though. One way to visualize transpiration is to put a plastic bag around some plant leaves. As this picture shows, transpired water will condense on the inside of the bag (this photo shows transpiration after 1 hour). During a growing season, a leaf will transpire many times more water than its own weight. An acre of corn gives off about 3,000-4,000 gallons (11,400-15,100 liters) of water each day, and a large oak tree can transpire 40,000 gallons (151,000 liters) per year.
Since water vapor also evaporates from the soil, we would have seen even more water vapor captured if we had wrapped the plastic bag around the soil as well.
What is evapotranspiration?
Evapo- for evaporation
Transpiration- for transpiration
Evapotranspiration is the sum of all processes by which water moves from the land surface to the atmosphere via evaporation and transpiration. Evapotranspiration includes water evaporation into the atmosphere from the soil surface, evaporation from the capillary fringe of the groundwater table, and evaporation from water bodies on land. Evapotranspiration also includes transpiration, which is the water movement from the soil to the atmosphere via plants. Transpiration occurs when plants take up liquid water from the soil and release water vapor into the air from their leaves.
10
6.3.1
Episode 5
11
6.3.1
Write an explanation to describe how energy from the sun, density, and gravitational forces are the driving factors for the cycling of water through the Earth’s systems.
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Explain how this cycling of water driven through Earth’s systems makes it possible for us to drink the same water as the dinosaurs.
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12
Create a model to communicate how the cycling of matter through Earth’s systems, driven by energy, explains how water drunk by dinosaurs is the same water drunk today.