Download Unit Outline: Biography of the Earth

Unit Outline: Biography of the Earth
Holding It All Together
1. Explain the two factors that affect the force of gravity
Mass of the two objects and the distance between them
2. What is Density?
Relationship between how much matter an object has and how much space it takes up. D = M/V
Mass is directly proportional to density. Volume is inversely proportional to density.
Formation Theories
3. Currently, what is the best accepted theory for the formation of the Universe? Describe that theory
and summarize the evidence for that theory.
Big Bang – Universe was once all condensed into a small, dense, object. It exploded and
expanded outward. The universe is continuing to expand and background radiation indicates that
the outside of the Universe is older than the inside.
4. What are the possible fates for the Universe and on what do these fates depend?
5. Currently, what is the best accepted theory for the formation of the Solar System? Describe that
theory, being sure to emphasize the role gravity played in the formation of the Solar System.
Nebular Hypothesis – Solar system began as a rotating cloud of dust and gas. Gravity made the
cloud condense. As the center condensed it became a protostar. When it was large enough,
nuclear fusion began it became a sun. The other material condensed to form the planets.
6. Currently, what is the best accepted theory for the formation of the Moon? Describe that theory.
7. Describe the origin and evolution of the atmosphere.
The original atmosphere came from the leftovers of the solar system. It blew off from solar
winds. The next atmosphere was the mostly gases and water vapor from volcanic eruptions. As
organisms evolved and began to produce oxygen, the CO2 levels dropped and O2 levels
increased. Finally ozone formed and life moved out on to land.
8. Describe the origin and evolution of the oceans.
The oceans are the result of water vapor produced from volcanoes condensing and raining. They
have become salty as runoff from the land dissolved salts from the land and deposited them in the
oceans.
9. Describe why the Earth, Atmosphere, Ocean, and Sun all have layers.
Because of density – the different layers are the result of different materials having different
densities – the more dense layers are at the center/bottom.
10. Compare the composition of the layers of the Earth, Atmosphere, Oceans, and Sun
Earth: Core – Fe and Ni, Mantle – Si and other materials, Crust – Si
Atmosphere: Mostly N, about a quarter O, rest is miscellaneous elements and compounds
Oceans: Water, Salt, Other elements and compounds
Sun: H, He
11. Compare the structure of the layers of the Earth, Atmosphere, Oceans, and Sun
Earth: Inner Core – Solid, Outer Core – Liquid, Mantle – Liquid, Lithosphere – Solid
Atmosphere – All gas, with pressure decreasing as you move away from earth
Ocean – All gas, with pressure increasing as you move down into the ocean
Sun – All gas
12. Compare the processes that occur with the layers of the Earth, Atmosphere, Oceans, and Sun
In all cases, hot stuff is less dense, so it rises, creating currents that rise, cool, fall, warm, rise…
Stellar Lifecycles
13. How do gravity and the nuclear processes involved in a star’s energy production relate to the lifecycle
of stars?
The larger the star, the more gravity and pressure. Therefore the hotter it burns. Therefore the
faster it uses its fuel. Smaller stars live longer.
14. Describe the life cycles of stars based on their mass.
Small: Nebular – Protostar – Main Sequence – White Dwarf – Black Dwarf
Medium: Nebula – Protostar – Main Sequence – RG – Planetary Nebula – WD – BD
Large: Nebula – Protostar – MS – SRG – Supernova – Black Hole or Neutron Star
Building and Wearing Forces
15. Differentiate between building forces and wearing forces that affect the Earth
Building Forces – Plate Tectonics – Build up the land – Mountain Building & Volcanoes
Wearing Forces – Weathering and Erosion – Wear Down the land
16. Compare continental crust with oceanic crust.
Continental Crust is made up of granite and is less dense
Oceanic Crust is made up of basalt and is more dense
Geochemical Cycles and Systems
17. List at least three geochemical cycles.
18. Explain how geochemical cycles move and conserve matter.
19. List at least three systems within the Earth System.
20. Explain how matter moves between the different Earth systems.
21. Describe why the Earth has not cooled down over the last 4.6 billion years.
22. What geochemical processes would be affected if the Earth cooled down?
23. What geochemical processes would be affected if the Sun stopped heating the Earth?
Geologic Time
24. What evidence suggests that the Earth is both very very old and has changed over time
Fossils, Rock Layers, Observations of current processes (i.e. mountains grow a few cm a year, so
the mountains we have must be millions of years old)
25. What types of processes have changed the Earth over the last 4.6 billion years?
Building forces make new land – islands, mountains, etc
Wearing forces wear the land down creating different landforms
Climates have changed
Desertification
26. How do we “know” that those processes occurred?
Looking at different layers of the earth in places like the Grand Canyon
27. Describe changes to Earth’s Climate during the last 4.6 billion years.
Earth has gone through many climate changes – Warm and dry. Ice ages. Often it is the result of
the movement of the continents. Large continents often have dry interiors. Slight changes in the
tilt of the Earth or atmospheric conditions can cause ice ages.
28. Describe changes to the Earth over the last 4.6 billion years.
Continents have changed
Landforms have changed
Climate has changed
Living things have changed
Oceans have changed
29. Describe the absolute and relative dating methods used to measure geologic time
30. Describe the types of information we get by studying fossils
Climate
Presence of water (oceans where now there are mountains)
Change in life