1. Earth’s Systems and Cycles

2. Essential questions
Describe the type of system Earth is and give your reasoning.
Describe what happens within a positive loop and give an example.
Give an example of Earth’s spheres interacting in your backyard. (state object, sphere it is in and how they interact)

3. Warm up What do you think of when you hear the word system?
Brainstorm a list of systems with the person next to you

4. Earth as a System
A system is a part of the universe that can be studied separately.
Scientists sometimes study individual parts of the Earth such as:
How mountains form
Classification of life forms
How tornadoes form
Today we understand that the all parts of the Earth are connected and interacting
The best way to understand the Earth is not to study the parts in isolation but as one system

5. Systems have Inputs and Outputs
SKETCH ON THE SIDE

6. Closed vs. Open Systems Closed Systems Open Systems
Matter does not enter or leave
Matter enters and leaves
Energy enters and leaves

7. Earth is a Closed System
Energy from the sun is absorbed by the Earth’s atmosphere and surface during the day
Energy is lost back into space at night as heat.
The matter on Earth is the same matter that was here when Earth formed.
Matter changes form but the TOTAL amount of matter remains the same.
Mt Etna lava picture source: :

8. How is a jar of sun tea like the Earth?
Sun tea is made with tea bags and water in a closed jar that is left out in the sun.
How is this similar to Earth as a closed system?

9. Except…. What happens when a meteorite hits Earth?
OR when NASA send up space ships or satellites?
A tiny amount of Hydrogen atoms are lost to space.
Overall, Earth is still considered a closed system.
This means our resources must be conserved and protected.

10. Feedback Loops
Within a system feedback loops are often identified to help define how the system works.
Feedback loops can either be positive or negative
Positive Feedback Loops: chain reactions that moves part of the system towards extremes (hi/lo)
Negative Feedback Loops: chain reactions that moves part of the system towards being stable

11. Bank Account
Body Temperature

13. Systems have feedback loops
Negative feedback – most common
Think of a thermostat
You set your thermostat for 70 degrees
It senses the air temperature is below 70 so it signals the heater to turn on
The heater warms the air in the room
The thermostat senses the temperature is at 70 so it signals the heater to turn off
This type of feedback helps to maintain equilibrium in a system

14. Positive Feedback loop from NASA

15. Positive Feedback
In a positive feedback loop, it’s like your foot is stuck on the accelerator and you keep going faster!
For more on systems and modeling, see
Systems Theory and Modelinghttp://science.csumb. edu/esse21/index.php
Image courtesy of Hugo Ahlenius, UNEP/GRID-Arendal Maps and Graphics Library.

16. Earth’s system includes 4 spheres that interact
The Atmosphere consists of the gases that surround the Earth = AIR
The Geosphere (also called lithosphere) consist of the rocks, minerals, soils, ocean basins and Earth’s interior = ROCK
The Hydrosphere includes the water in oceans, rivers, groundwater, clouds, lakes, ice caps and glaciers = WATER
The Cryosphere is sometimes used to describe frozen water in ice cap and glaciers
The Biosphere includes all things living or coming from living things. = LIFE
Visualize Earth’s spheres: ions/es0102/es0102page01.cfm?chapter_no=visualization

17. Earth’s Sphere’s Interact
An erupting volcano releases lava, volcanic bombs (geosphere) and gases and ash into the air (atmosphere), the animals are suffocated (biosphere), plants burn up (biosphere), ash flows fill rivers (hydrosphere).

18. More interaction examples
Plants and animals ( biosphere) breathe, taking in oxygen ( atmosphere) and releasing CO2.

19. More interaction examples Fill in the sphere names
People ( ) drill wells into the Earth’s crust ( ) drawing out groundwater ( ) used for drinking and irrigation.
Hurricanes form over the ocean ( ), sweep onto the shore ( ) and can damage homes and habitats ( ) on land.

20. Interacting Practice: What is interacting?
LIST the items along with what sphere they belong
LIST how the items are interacting with one another

21. Summary Describe the type of system Earth is and give your reasoning.
Describe what happens within a positive loop and give an example.
Give an example of Earth’s spheres interacting in your backyard. (state object, sphere it is in and how they interact)

22. Cycles involve interactions between the spheres
A cycle is a event or process that repeats over and over again.
Examples:
The water cycle
The carbon cycle
The nitrogen cycle
A biogeochemical cycle moves nutrients between living and nonliving portions of the Earth

23. The Water Cycle
Water leaves the oceans and other bodies of water through evaporation and the leaves of plants through transpiration.
Solar energy powers this part of the water cycle.
Water vapor cools and condenses to make cloud droplets or ice crystals that merge to form rain and other forms of precipitation.
Gravity pulls the precipitation back down to the surface.
See U.S.G.S for a quick summary:

24. Precipitation can be rain, snow, sleet or hail
Precipitation falls to the Earth
and either infiltrates into the ground,
becomes runoff that moves across the surface,
lands in a body of water
or is evaporated back up into the sky
Can you label A - G?
Rita Haberlin’s Lecture notes:

25. We Impact the Water Cycle
Developing land reduces the amount of water that can sink into the ground, infiltration and increases the amount of runoff that occurs.
This causes other problems such as:
Soil erosion
Loss of ground water recharge
Flooding
Pollution of lakes and streams
Judith Earl slideshow: