Earth’s Many Cycles

1. Earth’s Many Cycles 10 November 2015 Chapter 18 Presented by Dr. Geller Great Idea: All matter above and beneath Earth’s surface moves in cycles. 1

2. Chapter Outline • Cycles Small and Large • The Hydrologic Cycle • The Atmospheric Cycle • The Rock Cycle

3. Cycles Small and Large

4. Recycling • Where did the aluminum can go? • Atoms last virtually forever • Different forms • Lava flow bonded to oxygen • Solid rock • Soil • Aluminum metal • Recycling saves energy

5. The Nature of Earth’s Cycle • Earth materials move in cycles • A change in one cycle affects the others • Atoms constantly moving and recycling • Reservoirs • Hydrologic cycle • Atmospheric cycle • Rock cycle • Heat • Hotcold • Sources • Sun • Geothermal processes

6. iClicker Question • What are the Earth’s two primary sources of heat energy? • A solar energy and friction • B the Sun and geothermal processes • C atmospheric friction and forest fires

7. iClicker Question • Many of Earth’s cycles are driven by: • A Earth’s rotation • B tilt of the Earth’s axis • C the tendency of heat to spread out

8. The Hydrologic Cycle

9. Reservoirs of Water • Amount of water on earth is fixed • Major repositories • Ice caps • Glaciers • Unseen reservoirs • Groundwater • aquifers

10. Movements of Water Between Reservoirs • Hydrologic cycle • Short-term transfer of water between ocean and land

11. The path of groundwater

12. Ocean Currents • Redistribute heat across planet

13. Chemical Cycles in the Oceans • Chemicals in constant motion • Saltiness • Constant over several hundred million years • Primarily determined by Na+ and Cl- ions • Residence time • Chemical cycle

14. Ice Ages • Ice Age • Water locked in glaciers • Glaciers advance from poles • Current ice age • Interglacial period • Earth’s total water is fixed • Ice caps, glaciers grow • Sea level drops

15. Milankovitch Cycles • Milankovitch • Serbian civil engineer • Relationship between earth and sun are affected by variations in earth’s rotation and orbit • Precession • Change in angle of axis of rotation

16. iClicker Question • The combination of processes by which water moves from repository to repository above, below, and on the Earth’s surface is called the: • A aqueous cycle • B drought/drench ratio • C hydrologic cycle • D repository balance

17. iClicker Question • What percent of the Earth’s water is readily available for human use? • A less than 1 • B 5 • C 67 • D more than 98

18. iClicker Question • What percent of the Earth’s fresh water is stored as groundwater? • A less than 1 • B 5 • C 67 • D more than 98

19. iClicker Question • The saltiness of the ocean is • A Increasing • B Decreasing • C Remains the same

20. iClicker Question • What process removes atoms from the ocean? • A photosynthesis • B digestion by fishes and animals • C chemical reactions

21. iClicker Question • During an ice age, sea levels: • A drop • B rise • C remain constant

22. The Atmospheric Cycle

23. Atmosphere • Composition • Nitrogen (78%), Oxygen (21%), Argon, Water Vapor, CO2, Methane, other • Atmospheric Pressure • pressure exerted by atmosphere • Warming • Sun - solar constant is not really constant • greenhouse effect • warming due to the transparency of a substance to radiation at visible wavelengths and opacity to infrared radiation

24. The Greenhouse Effect • Solar energy is the energy source for the atmosphere • In the greenhouse effect, some of this energy is trapped by infrared absorbing gases in the atmosphere, raising the Earth’s surface temperature above what it would be if there was no greenhouse effect

28. Industrial chemicals released into the atmosphere have damaged the ozone layer in the stratosphere

29. The Earth’s atmosphere has changed substantially over time • The Earth’s atmosphere differs from those of the other terrestrial planets in its chemical composition, circulation pattern, and temperature profile • The Earth’s atmosphere changed from being mostly water vapor to being rich in carbon dioxide • A strong greenhouse effect kept the Earth warm enough for water to remain liquid and to permit the evolution of life

30. Structure of the Atmosphere

31. Air Masses: Reservoirs of the Atmosphere • Air mass • Uniform temperature and moisture • Weather • State of the atmosphere • Climate • Long-term average of weather

32. Weather • Five variables define state of atmosphere • Temperature • Ground level • Air pressure • Decreases with altitude • Jet stream • Humidity • Atmospheric water content • Cloudiness • Concentration of water droplets • Prevailing winds • Consequence of atmospheric convection

33. The General Circulation of the Atmosphere • Circulation powered by Sun • Air heated and rises • Cools and sinks • Prevailing winds • Caused by earth’s rotation

34. Common Storms and Weather Patterns • Severe weather • Tropical storms • Hurricanes • typhoons • Tornadoes • Weather cycle • El Nino

35. Climate • Little change over short periods • Influences on climate • Large bodies of water • Ocean currents • Mountain ranges • Earth’s climate • Movement of tectonic plates

36. Understanding Climate • Long-term climate • Oceans • Mountains • Sunlight • Amount radiated back to space • Prediction • Global circulation models

37. iClicker Question • The weather patterns in much of the Northern Hemisphere move, in general, from: • A north to south • B south to north • C east to west • D west to east

38. iClicker Question • Earth’s atmospheric cycle is not strongly influenced by other global cycles. • A True • B False

39. iClicker Question In what part of the atmosphere does weather occur? A hydrosphere B stratosphere C ionosphere D troposphere E all of the above

40. iClicker Question The greenhouse effect occurs largely because A a gas is transparent to visible light and opaque to infrared radiation. B a gas is transparent to infrared radiation and opaque to ultraviolet radiation. C ozone is transparent to ultraviolet radiation and opaque to infrared radiation. D methane is transparent to infrared radiation and opaque to visible light. E the sun emits more infrared radiation than ultraviolet radiation.

41. The Rock Cycle

42. Rock Cycle Overview

43. Igneous Rocks • Igneous Rocks • Solidify from hot liquid • Types • Extrusive • Solidify at surface • Intrusive • Solidify below surface

44. Sedimentary Rocks • Sedimentary rock • From grains of weathered rock • Formation • Compaction • Cementation • Examples • Sandstone • Shale • Limestone

45. Metamorphic Rocks • Metamorphic rock • Pressure and heat • Not enough heat to melt • Examples • Slate • Schists • Gneisses • Quartzite

46. The Story of Marble • Marble • Metamorphic rock • Process of formation • Begin as limestone • Subjected to heat and pressure • Erosion exposes rocks

47. Surface Building Processes • Faulting • formation of a crack caused by relative movement of rock on either side of a fracture • different types - normal, reverse, thrust

48. Mountains • “elevated parts of the Earth’s crust that rise abruptly above the surrounding surface” • Causes • folding, faulting, volcanic activity

49. Folds • bends in layered bedrock • Anticline /\ • Syncline \/

50. Volcanoes • “hill or mountain formed by the extrusion of lava or rock fragments from magma below” • Different types • shield, cinder cone, composite (composite shown)