1. How The Earth Works

3. The Solid Earth

4. Earth Science Geology –Solid Earth Much Larger than Other Parts –Many More Kinds of Materials –Preserves a History Meteorology – Climatology Oceanography Astronomy –Planetary Geology

5. Earth Systems External Effects (Astronomical) Atmospheric Circulation Oceanic Circulation Hydrologic Cycle Rock Cycle Plate Tectonics

6. Earth Systems

14. Convection

15. Earth and the Universe Rotation (Day-Night) Lunar (Tides) Annual (Seasons) Precession and Orbit Variations (Ice Ages?) Galactic (250 m.y. period) Unpredictable Events –Nearby Supernovae –Meteor Impacts Long-Term Evolution of Sun

16. Atmospheric Circulation Unequal Solar Heating –Equator to Pole –Day - Night –Different Surfaces Buoyancy Adiabatic Heating and Cooling Coriolis Effect High and Low Pressure Fronts and Air Masses

17. Rotation Effects

20. The Coriolis Effect Due to moving on a rotating earth Things on equator are moving faster than points near poles Affects: –Winds –Ocean Currents –Tides

21. The Coriolis Effect Things moving toward the equator are deflected west Things moving poleward are deflected east Counterclockwise in Northern Hemisphere Clockwise in Southern Hemisphere

22. Not a Manifestation of the Coriolis Effect! Too small scale for the Coriolis Effect to be significant

23. Atmospheric Circulation

24. 1905 Weather Map

25. Oceanic Circulation Surface Currents - Driven by Winds Thermohaline - Deep Circulation –Evaporation makes water more saline and denser –Freezing makes water more saline and denser –Cold water is denser than warm water

26. Early Map of Gulf Stream

27. Surface Currents

28. Thermohaline Circulation

29. Hydrologic Cycle Evaporation from Oceans Precipitation on Land –Infiltration into Ground (Ground Water) –Runoff (Erosion)

30. Hydrologic Cycle

31. Water Principal Agent in Modifying Earth’s Surface Medium for Storing and Distributing Global Heat The Universal Solvent –Essential for Life –Destructive to Rocks Lowers Melting Point of Rocks Reduces Strength of Rocks Under Pressure

32. The Rock Cycle New Rocks Exposed by Erosion Rocks Broken Down Mechanically and Chemically (Weathering) Components Transported by Erosion Components Cemented into Sedimentary Rocks Burial and Heating creates Metamorphic Rocks Melting Creates Igneous Rocks

33. The Rock Cycle

34. Plate Tectonics Outer Crust of Earth Moves a Few cm/yr Driven by Convection in Earth’s Interior Accounts For: –Earthquakes –Volcanoes –Mountain-Building (Orogeny) Configuration of Continents

35. Plate Tectonics

36. Plate Tectonics and Resources

37. Configuration of Continents Oceanic Circulation Weather and Climate Patterns –Deserts –Mountains and Rain Shadows Pathways for Migration Ecological Niches

38. Configuration of Continents

39. Some Unique Aspects of Geology Importance of Relationships Sequential Spatial Importance of Time Distinctive Problems of Evidence Slow Rates Rare Events Destruction of Evidence Inaccessibility

40. Some Geologic Rates Cutting of Grand Canyon 2 km/3 m.y. = 1 cm/15 yr Uplift of Alps 5 km/10 m.y. = 1 cm/20 yr. Opening of Atlantic 5000 km/180 m.y. = 2.8 cm/yr. Uplift of White Mtns. (N.H.) Granites 8 km/150 m.y. = 1 cm/190 yr.

41. Some Geologic Rates Movement of San Andreas Fault 5 cm/yr = 7 m/140 yr. Growth of Mt. St. Helens 3 km/30,000 yr = 10 cm/yr. Deposition of Niagara Dolomite 100 m/ 1 m.y.? = 1 cm/100 yr.

42. 1 Second = 1 Year 35 minutes to birth of Christ 1 hour+ to pyramids 3 hours to retreat of glaciers from Wisconsin 12 days = 1 million years 2 years to extinction of dinosaurs 14 years to age of Niagara Escarpment 31 years = 1 billion years

43. Some Unique Aspects of Geology (Continued) Reliance on Inference and Deduction Intrinsically "Unsolvable" Problems Ancient Landscapes Mass Extinctions Ancient Ocean Basins

44. Scientific Principles in Geology Parsimony (K.I.S.S.) Superposition Uniformitarianism Using these, plus observation, we establish facts about Earth Processes

45. Parsimony The simplest explanation that fits all the data is preferred Doesn’t guarantee that things must be simple! Theories with lots of ad hoc or unsupported ideas are probably wrong.

46. Superposition: Mindoro Cut, Wisconsin

47. Geologic Map

48. Uniformitarianism Continuity of Cause and Effect Apply Cause and Effect to Future - Prediction Apply Cause and Effect to Present - Technology Apply Cause and Effect to Past - Uniformitarianism