1. EARTH SYSTEMS

2. EARTH’S LAYERS http://www.english-online.at/science/geologic-history-of-the-earth/geologic-eras-of-the-earths-history.htm Core: nickel and iron solid Liquid Magma – slowly circulates in convection cells Semi-molten rock (flexible) Made up of plates

3. THEORY OF PLATE TECTONICS Alfred Wegener – “Pangaea” Plate Tectonics a. earth’s lithosphere is divided into plates, most of which are in constant motion b. continental and oceanic plates - movement driven by convection cells

4. Plate Boundaries a. Divergent - beneath the oceans - seafloor spreading (brings up important elements) b. Convergent - plates collide - subduction (responsible for the Andes in SA) - mountain formation (Himalayas in Asia) c. Transform Fault - plates slide past each other - “San Andreas Fault”

5. Consequences of Plate Movement a. Earthquakes - occurs when rocks of the lithosphere rupture unexpectedly along a fault - fault zones/seismic activity - Richter Scale * measurement of ground movement * increases by a factor of 10

6. b. volcano - occurs as a plate moves over a hot spot and heat from the mantle melts the crust - as plate moves past the hot spot, leaves behind a trail of extinct volcanic islands (The Hawaiian Islands)

7. ROCK CYCLE “constant formation and destruction of rock” Slowest of all Earth’s cycles Rock : composed of one or more minerals Mineral : solid chemical substance with uniform composition

8. 3 types of rocks a. Igneous b. Sedimentary c. Metamorphic

9. Igneous Rocks a. form directly from magma b. basaltic vs. granitic c. intrusive vs. extrusive http://geology.com/rocks/igneous-rocks.shtml http://earth.usc.edu/~slund/systems/topic7.html

10. Sedimentary Rocks a. form from sediments being compressed by other overlying sediments b. typically uniform in composition c. sink for phosphorus d. fossil record http://saturniancosmology.org/files/geology/sect2_1a.html

11. Metamorphic Rocks a. formed when rocks are exposed to extreme temperature and pressures ex) collision of tectonic plates b. structurally strong rocks

12. WEATHERING AND EROSION Weathering a. occurs when rock is exposed to air, water, chemical compounds, animals, etc. b. 2 types - physical * mechanical breakdown of rocks * water, wind, burrowing animals

13. - chemical * breakdown by chemical reactions * acid deposition (“acid rain”)  S emitted into atmosphere, combines with O 2 and forms SO 2, SO 2 reacts with water vapor to form sulfuric acid  rapid degradation of gravestones, marble, limestone

14. Erosion a. “physical removal of rock from a landscape or ecosystem” b. wind, water, animals c. deposition d. acceleration of erosion - deforestation, overgrazing, road building

15. SOIL Benefits of soil a. plant growth b. primary filter of water c. provides habitat d. filters chemical compounds deposited by air pollution

16. Soil Formation a. result of physical and chemical weathering of rocks and gradual accumulation of detritus from the biosphere b. mix of mineral and organic components c. 5 factors - parent material - climate - topography - organisms - time

17. Soil Horizons http://en.wikipedia.org/wiki/Soil_horizon Organic material in various stages of decomposition “topsoil”; zone of organic material and minerals mixed together E Horizon: “zone of leaching” in acidic soils (found below O) “subsoil”; zone of nutrients Least weathered layer; similar to parent material

18. Soil Properties a. physical - texture * determined by percentage of sand, silt, and clay * ex) 40% sand, 40% silt, 20% clay - __________ 70% sand, 20% silt, 10% clay - __________ http://www.soilsensor.com/images/soiltriangle_large.jpg

19. * porosity  determines water holding capacity of soil  depends on texture http://www.eoearth.org/view/article/149751/

20. b. chemical - CEC * cation exchange capacity * nutrient holding capacity * depends on amount of clay particles present - base saturation * soil bases to acids * bases (neutralizers)  Ca, K, Mg, Na acids (detrimental)  Al, H

21. c. biological - fungi, bacteria, protozoans - fix nitrogen (essential for plant growth) http://urbanext.illinois.edu/soil/SoilBiology/images/A-3.jpg

22. Soil Degradation a. loss of ability of soil to support plant growth b. due to overuse of land c. one major cause = soil erosion (topsoil disturbed) http://www.landfood.ubc.ca/soil200/soil_mgmt/soil_degradation.htm

23. MINERAL RESOURCES Ores – concentrated accumulation of minerals from which economically valuable materials can be extracted - characterized by presence of valuable metals Metals – elements with properties that allow them to conduct electricity and heat energy and perform other functions Reserve – known quantity of a resource that can be economically recovered

24. Mining a. extracting mineral resources b. Types of mining 1. strip mining - removal of “strips” of soil and rock to expose ore - “coal and sand” - return tailing or spoils back to hole 2. open-pit mining - creating of large hole visible from Earth’s surface - “copper mines”

25. 3. mountaintop removal - remove entire top of mountain with explosives - deposits tailings in lower elevation 4. placer mining - use of river water to separate heavier items - example: diamonds, gold 5. subsurface mining - below earth’s surface - “coal, diamonds, and goal”

26. Mining Safety - produces tailings which contaminate land and water with acids and metals - subsurface mining * acid mine drainage * accidental burial * inhalation of gases and particles (black lung disease) * explosions

27. Mining Regulation - Mining Law of 1872 * regulate mining of silver, copper, gold ore, natural gas and oil on federal lands - Surface Mining Control/Reclamation Act * mandates that land disturbed must be reclaimed after mining process