Geology. Geology is the study of the dynamic process occurring on the earth s surface and in its interior

Transcription

1 Resources & Energy

2 Geology Geology is the study of the dynamic process occurring on the earth s surface and in its interior

3 Earth s Structure

4 Core innermost zone made up of iron and nickel. Inner Core: solid inner core Outer Core: molten inner core Mantle middle zone made primarily of solid rock with an outer layer that is molten pliable rock Crust outermost layer

5 Geologic Processes The solid lithosphere is divided into large plates called tectonic plates. E.g. North American Plate, Pacific Plate, etc. Tectonic plates sit on top of large volumes of hot and molten rock. Convection cells or currents in the earth s interior cause the tectonic plates to move slowly across the earth s surface.

6 Hadley Cells & Climate Zones

7 Collision between two continents Spreading center Ocean trench Subduction zone Continental crust Mantle convection cell Oceanic crust Material cools as it reaches the outer mantle Hot material rising through the mantle Oceanic crust Cold dense material falls back through mantle Continental crust Two plates move towards each other. One is subducted back into the mantle on a falling convection current. Hot outer core Inner core Mantle Fig. 15-3, p. 337

8 GEOLOGIC PROCESSES Figure 15-2

9 The Earth s Major Tectonic Plates Figure 15-4

10 Plate Tectonics The theory that explains the movement of the plates and the processes that occur at their boundaries

11 The Largest Plate Pacific Plate The North American plate shares a boundary with the Pacific Plate on the west coast It is the location of the ring of fire

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13 Plate Boundaries Divergent plates move apart in opposite directions

14 Convergent plates move towards each other. Oceanic Lithosphere is often pushed under Continental Lithosphere. This is called a subduction zone. Earthquakes & volcanoes are common at this type of boundary. Ocean ridges and mountains commonly form at these boundaries as well

15 Convergent Boundary

16 Transform Boundary Plates slide past each other in opposite directions

17 GEOLOGIC PROCESSES The San Andreas Fault is an example of a transform boundary. Figure 15-5

18 The Importance of Geological Processes Plate movement adds new land, makes mountains, ridges, trenches, and causes earthquakes and volcanoes

19 Rock Cycle Processes that form rocks and change rocks from one type into another Uplift Weathering Erosion Transportation Deposition Sedimentary Rock Metamorphic Rock Igneous Rock

20 Transportation Erosion Weathering Deposition Sedimentary rock Sandstone, limestone Heat, pressure Igneous rock Granite, pumice, basalt Cooling Heat, pressure, stress Magma (molten rock) Melting Metamorphic rock Slate, marble, gneiss, quartzite Fig. 15-8, p. 343

21 Steps

22 Types of Rock Sedimentary Examples: sandstone, conglomerate & breccia; limestone, peat, coal Metamorphic Examples: Marble (limestone), Quartzite (sandstone), graphite (coal) Igneous Forms the bulk of the Earth s crust. Source of many non fuel mineral resources Examples: ruby, sapphire, diamond

23 Extraction of Mineral Resources Extraction, processing & use of mineral resources have a large environmental impact. The method of extraction depends on the mineral being extracted, the topography of the land, and the depth of the resource

24 Surface & Subsurface Mining Surface Mining Mineral deposit is < 200ft deep Topsoil is removed and saved Overburden material (e.g. rocks) on top of ore Spoil Banks piles of removed overburden Severely degrades the landscape Types of surface mines Open Pit Area & Contour Strip Mine Mountain top removal

25 Open Pit Mine

26 Area & Contour Strip Mines

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28 Mountain Top Removal

29 Subsurface Mining Mineral deposit is > 200ft deep Dig shafts down to the resource Degrades less land than surface mining

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31 Reclamation Overburden is returned, some soil is returned, fertilized and then planted.

32 Energy Resources Renewable Vs. Nonrenewable Nonrenewable Coal Oil Natural Gas Uranium

33 Coal Solid fossil fuel formed from the remains of buried land plants ( mya)

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35 Where s the Coal?

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37 Oil Crude oil (petroleum) is refined or separated into various petroleum products. Gasoline, diesel fuel, jet fuel asphalt Light (conventional) 35-50% of the oil deposit Heavy (unconventional) 50-65% of the oil deposit

38 Where s the Oil?

39 Unconventional Oil Resources Shale Oil Sedimentary rock containing kerogen can be heated to produce shale oil.

40 Oil Sands Oil containing sand can be processed to yield oil. 2 tons of sand/barrel of oil 3 barrels of water/barrel of oil

41 Oil Production U.S. oil production peaked in the 1970 s World oil production is projected to peak between Oil supplies are projected to last more years Arab Oil Embargo 0f 1973 Response to Yom Kippur War U.S. supported Israel

42 Natural Gas Composed primarily methane gas Found above reserves of crude oil (i.e. conventional) Versatile & relatively clean burning

43 Where s the Natural Gas?

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45 Nuclear Energy Fission of uranium atoms generates heat. Heat is used to produce steam. Steam turns a turbine. Uranium ore only contains.7% U-235 and 99.3% U-238 Uranium must be enriched to between 3-4%

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47 Uranium fuel input (reactor core) Small amounts of radioactive gases Control rods Containment shell Heat exchanger Steam Turbine Waste heat Generator Electric power Hot water output Useful energy 25% 30% Shielding Pressure vessel Periodic removal and storage of radioactive wastes and spent fuel assemblies Coolant Moderator Coolant passage Water Periodic removal and storage of radioactive liquid wastes Condenser Cool water input Waste heat Water source (river, lake, ocean) Fig , p. 372

48 Nuclear Waste One of the major problems with nuclear energy is figuring out what to do with the waste.

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50 Energy Resources Renewable Vs. Nonrenewable Renewable Solar Water Wind Geothermal

51 Solar Active Vs. Passive Active Photovoltaic cells Convert light into electricity Solar thermal systems Convert light into heat. The heat can be used to water, produce steam and turn a turbine.

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54 Single solar cell Solar-cell roof + Boron enriched silicon Junction Roof options Phosphorus enriched silicon Panels of solar cells Solar shingles Fig , p. 398

55 Producing Electricity with Solar Cells Solar cells can be used in rural villages with ample sunlight that are not connected to an electrical grid. Figure 17-18

56 Passive using sunlight to heat a space and insulation to prevent the heat from escaping.

57 Direct Gain Ceiling and north wall heavily insulated Hot air Summer sun Warm air Superinsulated windows Winter sun Cool air Earth tubes Fig , p. 396

58 Water Power generated by harnessing the movement of water. U.S. has already tapped 98% of its hydro potential Pollution Free Rivers: Dams Ocean: Waves & Tide

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60 Wind Power generated by harnessing the movement of wind. Fastest growing energy source Pollution Free

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64 Geothermal Geothermal Heat Pump Takes advantage of the temperature difference between the surface and a depth of about 10 The temp at 10 is between degrees F

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66 Geothermal Power Plant Uses steam directly from the Earth or heat from the Earth to produce steam. The steam then turns the turbine.

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69 Alternative Fuels Biomass any type of organic matter that can be used to produce energy Peat, Animal dung Ethanol & Methanol Biogas

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73 Producing Ethanol Corn, sugarcane, switch grass, and municipal solid waste can be converted into ethanol 10-23% gasohol (ethanol + gasoline) can be used in conventional motors. E-85 (85% ethanol) must be burned in flex fuel motors.

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75 Internal Combustion, Hybrid & Electric Vehicles Internal Combustion: gas engine Hybrid: e.g. gas-electric engines Electric: electric engine

76 Regulator: Controls flow of power between electric motor and battery bank. Transmission: Efficient 5-speed automatic transmission. Fuel tank: Liquid fuel such as gasoline, diesel, or ethanol runs small combustion engine. Battery: High-density battery powers electric motor for increased power. Combustion engine: Small, efficient internal combustion engine powers vehicle with low emmissions; shuts off at low speeds and stops. Electric motor: Traction drive provides additional power for passing and acceleration; excess energy recovered during braking is used to help power motor. Fuel Electricity Fig. 17-7, p. 389

77 Fuel-Cell Vehicles Fuel Cell: uses hydrogen gas as fuel. Electricity or heat is applied to water to create hydrogen gas. Emits water vapor.

78 Air system management Fuel-cell stack Converts hydrogen fuel into electricity Body attachments Universal docking connection Mechanical locks that secure the Connects the chassis with the body to the chassis drive-by-wire system in the body Rear crush zone Absorbs crash energy Front crush zone Absorbs crash energy Hydrogen fuel tanks Drive-by-wire system controls Cabin heating unit Side-mounted radiators Release heat generated by the fuel cell, vehicle electronics, and wheel motors Electric wheel motors Provide four-wheel drive; have built-in brakes Fig. 17-8, p. 390

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