Chapter 2 Earth as a System

1. Chapter 2 Earth as a System

2. 2.1 Earth: a Unique Planet • Only known planet that: • Has liquid water on its surface. • Has an atmosphere that contains Oxygen gas • Supports life • Formed 4.6 billion years ago • Not a perfect circle. Oblate sphere. Pg 27 • Equatorial Circumference 40,074 km

3. 2.1 Compositional Zones of Earth’s Interior • Crust- the thin, solid, outermost zone of Earth. • Continental Crust- 15 to 80 km thick • Oceanic Crust- 5-10 km thick • Mantle- layer that underlies the crust. • Denser than the crust. • 2,900 km thick- makes up 2/3 of Earth’s mass • Core- The center of Earth • Sphere shaped • 3,500 km thick • Composed of Iron and Nickel

4. 2.1 Structural Zones of Earth’s Interior • Lithosphere- The solid, outer layer of Earth that consists of the crust and the rigid upper part of the mantle. 15-300 km thick • Asthenosphere- The solid, plastic layer of the mantle beneath the lithosphere; made of mantle rock that flows very slowly, which allows tectonic plates to move on top of it. 200-250 km thick. • Mesosphere- literally, the ‘middle sphere”’ the strong, lower part of the mantle between the asthenosphere and the outer core. • Outer Core-Dense liquid underneath the Mesosphere 2,900 km down • Inner Core- Dense, rigid solid. Center of the Earth. 5,150 km down.

5. 2.1 Earth as a Magnetic • Earth has a North and South Pole • Pg 29 Figure 3 Earth’s magnetic field extends beyond the Earth’s Atmosphere and affects a region of space called the magnetosphere. • Source of Magnetic Field may be the liquid iron in Earth’s outer core. Motions within the core produce electric currents that in turn create Earth’s magnetic field. • Recent studies indicate that the sun and moon also have magnetic fields. Research in this field can help understand how we have our magnetic field.

6. 2.1 Earth’s Gravity • Gravity is the force of attraction that exists between all matter in the universe. • Newton’s Law of Gravitation states that, “the force of attraction between any two objects depends on the masses of the objects and the distance between the objects” • The larger and closer the objects are, the greater the force of gravity is.

7. 2.2 Energy in the Earth system • System-An organized group of related object or components that interact to create a whole • They can be closed or open systems

8. 2.2 Energy in the Earth system • Matter vs Energy • Matter- Anything that has mass and takes up space. • Made of atoms and/or molecules • Energy-the ability to do work • Transforms into heat, light, vibrations, or waves • Both can be transferred (or moved) into a system or out of a system

9. 2.1 Systems • Closed System: A system in which energy, but not matter is exchanged with the surroundings • Pg 32 Closed Jar- Energy in the form of light and heat can be exchanged through the sides. Because the jar is closed no matter can be exchanged with a closed container. • Open System: A system in which both energy and matter can be exchanged with the surroundings. • Open Jar, lake, • Earth is considered a system-A closed system because matter exchange is limited.

10. First Law of Thermodynamics • Law of Conservation of Matter: • States “Matter cannot be created or destroyed.” • It instead, transforms or changes. • Example: As a chemical breaks down from a reaction it releases energy in the form of heat.

11. Pg 33-35 Outline Notes

12. Earth’s Four Systems • The Atmosphere • 78% Nitrogen, 21% Oxygen, 1% other • The Hydrosphere • 71% of earth covered in water • Only 3% is fresh water • The Geosphere • Largest solid part of earth • The Biosphere • Composed of all the forms of life/organic matter

13. Earth’s Energy Budget • First Law of Thermodynamics • Conservation of energy and matter • Second Law of Thermodynamics • “When energy transfer takes place, matter becomes less organized with time” • Universe’s energy is spread out more and more uniformly over time

14. Internal Sources of Energy • Pg 35 “The Earth’s interior was headed by radioactive decay and gravitational contraction” • What does this mean? • The Idea of convection • Warm things rise…..why??? • Why is it important….well this process drives the plate motions in the surface layers of the geosphere that create mountain ranges and ocean basins.

15. External Energy Sources • The Sun • Solar radiation warms Earth’s atmosphere and surface • Convection of air masses causes winds and ocean currents • Gravitational Energy • From moon and sun cause tides/currents

16. Cycles of the Earth system • Nitrogen Cycle Pg 36 • Builds protein that builds cells • Carbon Cycle Pg 37 • Essential substances in the fuels used for life processes. • Phosphorus Cycle Pg 37 • Part of some molecules that organism need to build cells • Phosphorus was discovered from extracting it from urine. • Water Cycle Pg 38

17. 2.3 Ecology

18. Ecology • The study of the complex relationships between living things and their nonliving, or abiotic environment.

19. Ecosystems • A community of organisms and the environment that the organisms inhabit is called an ecosystem. • As large as an ocean or as small as a rotting log. • Largest ecosystem is the biosphere • Energy flows through these ecosystems • producers, consumers, decomposers (food webs) • Any examples?

20. Balancing Forces in Ecosystems • Organisms in an ecosystem use matter and energy. • Amounts of matter and energy are limited • The largest population that an environment can support at any given time is called the carrying capacity.

21. Energy Transfer • Starts with the Sun and photosynthesis • Photosynthesis captures energy that then flows through ecosystems from the plants, to the animals that feed on the plants, and finally to the decomposers of animals and plant remains. • Food Webs Pg 41 • What is an Energy Pyramid? Let’s talk about efficiently of a food web.

22. Create your Own food web • Create your own food web using the different animals either in the movie “The Lion King” • How does the song “The Cycle of Life” related to this food web?