Earth as a System
What Is A System? The interaction between matter, energy, and life. 3 principles that apply: Matter cycles Energy Flows Life Webs
Two Types of Systems Closed Chemicals (matter) important to life move in cycles (Water cycle, CO2 cycle, Rock cycle) Amount of matter stays the same-nothing added nor lost to the system.
Systems cont. Open Energy from sun enters system (Earth) Heat energy flows out to space. Energy is added and lost from the Earth.
Open or Closed Systems?
Past Perceptions of Earth Studied as a collection of parts. Was studied from the surface.
20th Century Lead to New Understandings Earth has interacting spheres, affect one-affect all. Understanding came about because of environmental incidents. (ozone depletion, oil spills, cutting down the rain forest, etc.) Technology allowed us to see Earth from a different perspective. New perspective.
Technology Computers & software allow for modeling and interpretation of data GIS Discovery And to see Earth from a different celestial body
4 Spheres of the Earth
Interaction of the Spheres Earth
Atmosphere Gaseous envelope Mixture of Gases Nitrogen, Oxygen, CO2, Argon, Water vapor. Allows life (O2 CO2) Protects from UV (O3) Water vapor drives weather systems. CO2 regulates temperature Original atmosphere:CO2, H2O, S 90% of all gases in first 16 km of the atmosphere.
Geosphere Physical Features, (mountains, rocks, beaches, ocean floor) 7-70 km thick Composition: Al, K, Ca, Fe, Mg, silicates Density: 2.8-3.0 g/cm3 Age: 4by-180my
Hydrosphere Oceans cover 71% of surface, 97% of all water. Avg. depth 3,800 m. 3% is fresh water but 70% is frozen (CRYOSPHERE) and 20% is ground & surface water ½ of 1% is useable fresh water Formed from degassing and comet impact All water is recycled (closed system)
Biosphere All living things of the planet; protozoa-fish- plants-people. Interactions of the spheres allow for conditions to support life. Human impact has changed & altered the other spheres. Extremophiles
Extremophiles Thermophiles Halophiles Black Smokers Morning Glory Pool, Yellowstone, MT Great Salt Lake, UT Juan De Fuca Ridge, Pacific Ocean
What Do You Know? What are Earth’s subsystems? How do satellites help us understand the Earth as a system? How does the Sun’s energy affect the oceans, atmosphere and life on Earth? What is the role of the atmosphere and oceans on the average temperature of the Earth? How is the Earth changing and what are the consequences for life on Earth?
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