1. Earth as a System Ch. 1 What is the Earth system, and where do we humans fit in?

2. A New View of Earth What do earth scientists study? – solid earth, oceans, oceans, space In past  studied separate parts – How has this changed? Why? » now often studied as a system b/c realized parts are connected and interact

3. A New View of Earth What sparked this new view of Earth as system? –space exploration “blue marble” photo (Apollo 17) –satellite imaging –environmental incidents –deep sea exploration –computers & Geographic Information Systems (GIS)

4. Models & Systems What is a model? – a simplified representation of an object, process, or phenomenon – a way to predict if-then scenarios (for the past & future) What happens when scientists learn more about the world? – Models can be modified or replaced with a new model What is a system? – group of objects or phenomena that share matter & energy Ex. Earth’s spheres – A type of model

5. Open & Closed Systems What is an open system? – a system & its surroundings that exchange energy & matter How is a closed system different from an open system? – energy can be exchanged… matter CAN’T be exchanged Is Earth an open system or a closed system? Why? – technically, open, but usually considered closed b/c exchange of matter is extremely small

6. Earth’s Spheres Examples of how the spheres interact & changes that result…

7. Overall, Earth is in balance… Changes to one sphere can have impacts on one or more or the others – human activities have major impacts on the spheres However, overall, Earth is in balance. How? – biogeochemical cycles carbon cycle water cycle rock cycle … and more

8. Carbon & Oxygen Cycles

9. The Water Cycle EXHALATION

10. Nitrogen Cycle

11. Sulfur Cycle

12. Phosphorous Cycle

13. Sediments Erosion Weathering Deposition Igneous rock Granite, pumice, basalt Sedimentary rock sandstone, limestone Heat, pressure Cooling & solidification Heat, pressure (metamorphism) Magma (molten rock) Melting Metamorphic rock slate, marble, gneiss, quartzite Rock Cycle

14. The Energy Budget “energy budget” is sometimes called “energy cycle” or “energy balance” – amount of energy that enters should equal amount that exits What happens if more energy enters? – heating What happens if more energy enters? – cooling

15. The Energy Budget & the Laws of Thermodynamics Can energy be created or destroyed? – No, it can only be transferred & transformed (1 st Law) Can energy ever be recycled completely? – No, when energy changes it is degraded into a less useful form & “lost” (in terms of its original form) (2 nd law) “Lost” energy is usually given off as…? – heat Chemical energy (food) Solar energy Waste Heat Waste Heat Waste Heat Waste Heat Mechanical energy (moving, thinking, living) Chemical energy (photosynthesis)

16. Earth’s Surface & the Energy Cycle How can Earth’s surface affect the energy budget? – “albedo” is the ability of a surface to reflect light What type of surfaces would have a low “albedo”? – dark & dull What type of surfaces would have a high “albedo”? – light & shiny – changes in surface type change the energy budget Factors Affecting Rates of Temperature Change Visualization