The Earth’s Interior Composed of 4 layers Crust Mantle Outer Core Inner Core
Crust Temperature: Over 175 degrees Celsius Topmost layer of the Earth Relatively cool Made of rock 2 types of crust Oceanic (4-7 km thick) Continental (20-40 km thick)
Mantle Temperature: Over 1250 degrees Celsius Makes up about 80% of the Earth’s volume ~ 2900 km thick Outer mantle – rocks Inner mantle – “plastic”
Core Temperature: Over 6000 degrees Celsius Outer core – liquid Pressure from the mantle & crust do not allow the metals in the outer core to become gasses Inner core – solid Pressure from the mantle and crust do not allow the metals to become liquid
Plate Tectonics The Earth’s lithosphere is made up of 7 tectonic plates Plate tectonics – the movement of these lithospheric plates
Focus = point of earthquake origination Epicenter = point on the Earth’s surface directly above the focus
Energy from an earthquake Energy is released in the forms of waves P wave: Primary or longitudinal waves originate from the focus & move quickly through rock. These are the first waves to be recorded S wave: Secondary or transverse waves originate from the focus & moves more slowly through rock. Surface waves: move across the earth’s surface, causes building to collapse
Earthquake Measurement Seismograph Records data about P, S and surface waves Used to locate the epicenter of an earthquake Richter scale Measures energy released at the epicenter of an earthquake (in magnitude) Each step up in magnitude represents a 30-fold increase in energy released!
Volcanoes Volcanoes result from openings or vents in the Earth’s surface Magma reaches the surface through these vents When magma reaches the surface it changes physically and is called lava
Shield Volcano Formed from fluid lava, rich in iron Shield volcanoes are large Mauna Loa in Hawaii
Composite Volcano Made of alternating layers of lava, ash and cinders. Magma is rich in silica and thick Large with steep slopes
Cinder Cone Large amounts of gas are trapped in the magma causing violent eruptions Active for short periods of time
Minerals & Rocks Minerals: naturally occurring, inorganic substances (inorganic = does not contain Carbon) can be expressed by a chemical formula Quartz SiO2 (silicon dioxide) Rocks: Composed of minerals
Types of Rock Igneous Formed when magma or lava cools and hardens Magma forms intrusive igneous rock Lava forms extrusive igneous rock Sedimentary Formed when rock particles, plant and animal debris are carried away by water, redeposited, then fused together Metamorphic Rock particles are fused together by pressure beneath the Earth’s surface
Determining the age of rocks Two ways to “determine” the age of a rock: 1.Superposition – determine the age based on layers, older rocks are on the bottom, newer ones on top 2.Radioactive dating
Weathering and Erosion Two types of weathering Physical Breaks rocks into smaller pieces, chemical composition does not change May be caused by ice or plants Chemical Changes the chemical composition of rocks May be caused by oxidation or acid rain
Erosion Erosion: the process of loosening and removing sediment Caused by water, glaciers, wind
Deposition Occurs when loose sediment is laid down Causes river beds to widen and deltas to form.
Important Elements Oxygen – most abundant element in the Earth’s crust Nitrogen – most abundant element in the atmosphere Iron – most abundant element in the core
Non-renewable Resources Defined: An energy source that cannot be renewed in our lifetime Examples: Oil Natural Gas Coal Aluminum Gold Uranium
Surface Mining Description – if resource is <200 ft. from the surface, the topsoil is removed (and saved), explosives are used to break up the rocks and to remove the resource, reclamation follows Benefits – cheap, easy, efficient Costs – tears up the land (temporarily), byproducts produce an acid that can accumulate in rivers and lakes
Underground Mining Description – digging a shaft down to the resource, using machinery (and people) to tear off and remove the resource Benefits – can get to resources far underground Costs – more expensive, more time-consuming, more dangerous – mining accident in Chile
Coal formed from ancient peat bogs (swamps) that were under pressure as they were covered. Used for electricity, heat, steel, exports, and industry, may contribute to the “Greenhouse Effect” Four types of coal exist: lignite (soft, used for electricity), bituminous and subbituminous (harder, also used for electricity) and anthracite (hardest, used for heating) 50% of all the coal is in the United States, the former Soviet Union and China
Fig. 16-12, p. 368 Increasing heat and carbon content Increasing moisture content Peat (not a coal) Lignite (brown coal) Bituminous (soft coal) Anthracite (hard coal) Heat Pressure Partially decayed plant matter in swamps and bogs; low heat content Low heat content; low sulfur content; limited supplies in most areas Extensively used as a fuel because of its high heat content and large supplies; normally has a high sulfur content Highly desirable fuel because of its high heat content and low sulfur content; supplies are limited in most areas
COAL Coal reserves in the United States, Russia, and China could last hundreds to over a thousand years. The U.S. has 27% of the world’s proven coal reserves, followed by Russia (17%), and China (13%). In 2005, China and the U.S. accounted for 53% of the global coal consumption.
Reclamation returning the rock layer and the topsoil to a surface mine, fertilizing and planting it Benefits – restores land to good condition Costs – expensive, time-consuming In the United States, mining companies are required to do this!
Open-pit Mining Machines dig holes and remove ores, sand, gravel, and stone. Toxic groundwater can accumulate at the bottom. Figure 15-11
Area Strip Mining Earth movers strips away overburden, and giant shovels removes mineral deposit. Often leaves highly erodible hills of rubble called spoil banks. Figure 15-12
Contour Strip Mining Used on hilly or mountainous terrain. Unless the land is restored, a wall of dirt is left in front of a highly erodible bank called a highwall. Figure 15-13
Mountaintop Removal Machinery removes the tops of mountains to expose coal. The resulting waste rock and dirt are dumped into the streams and valleys below. Figure 15-14
United States mining Central – diamonds (Arkansas), bituminous coal West – bituminous and subbituminous coal, gold, silver, copper East – anthracite coal, bituminous coal South – some gold (SC), bituminous coal North – bituminous coal, some gold (SD, WI)
Energy from non-renewable resources Cogeneration Primary Secondary
Fossil Fuels Only about 30% efficient Benefits – easy to use, currently abundant Costs – a nonrenewable resource, produces pollutants that contribute to acid rain and the greenhouse effect Oil- Supplies the most commercial energy in the world today. People in the U.S. use 23 barrels of petroleum per person or 6 billion barrels total each year!!!
OIL Eleven OPEC (Organization of Petroleum Exporting Countries) have 78% of the world’s proven oil reserves and most of the world’s unproven reserves. After global production peaks and begins a slow decline, oil prices will rise and could threaten the economies of countries that have not shifted to new energy alternatives.
Case Study: U.S. Oil Supplies The U.S. – the world’s largest oil user – has only 2.9% of the world’s proven oil reserves. U.S oil production peaked in 1974 (halfway production point). About 60% of U.S oil imports goes through refineries in hurricane-prone regions of the Gulf Coast.
Heavy Oils from Oil Sand and Oil Shale: Will Sticky Black Gold Save Us? Heavy and tarlike oils from oil sand and oil shale could supplement conventional oil, but there are environmental problems. High sulfur content. Extracting and processing produces: Toxic sludge Uses and contaminates larges volumes of water Requires large inputs of natural gas which reduces net energy yield.
Oil Shales Oil shales contain a solid combustible mixture of hydrocarbons called kerogen. Figure 16-9
Core Case Study: How Long Will the Oil Party Last? We have three options: Look for more oil. Use or waste less oil. Use something else. Figure 16-1
NATURAL GAS Natural gas, consisting mostly of methane, is often found above reservoirs of crude oil. When a natural gas-field is tapped, gasses are liquefied and removed as liquefied petroleum gas (LPG). Coal beds and bubbles of methane trapped in ice crystals deep under the arctic permafrost and beneath deep-ocean sediments are unconventional sources of natural gas.
NATURAL GAS Russia and Iran have almost half of the world’s reserves of conventional gas, and global reserves should last 62-125 years. Natural gas is versatile and clean-burning fuel, but it releases the greenhouse gases carbon dioxide (when burned) and methane (from leaks) into the troposphere.
Energy Efficiency – Non- renewable energy sources Coal, Natural Gas, Oil: about 30% efficient Nuclear:
Laws of Thermodynamics 1 st law: Conservation of Energy Energy cannot be created nor destroyed Energy can be transferred from one system to another 2 nd law: Energy transfer must only have one direction Entropy (disorder) increases over time 3 rd law: Absolute zero is achieved when all kinetic energy stops
SO….. 1 st law of Thermodynamics Explains how we can convert energy from chemical or mechanical energy to usable electric energy windmill animation 2 nd law of Thermodynamics explains WHY energy efficiency can be so low
Solar Solar energy is harnessing energy from the sun’s rays Passive Solar – Placing buildings strategically to take advantage of the sun’s heat Example: Log Homes Active Solar – uses solar panels to convert energy into a usable form such as electricity
Fig. 17-17, p. 398 Single solar cell Solar-cell roof – Boron enriched silicon + Junction Phosphorus enriched silicon Roof options Panels of solar cells Solar shingles
Benefits of Solar: Readily available Renewable Fairly simple system Pollution free energy source Can sell back extra energy to the power company Drawbacks of Solar: High start up cost for active solar energy system Location dependent (Seattle would not be a good city for solar energy)
Core Case Study: The Coming Energy-Efficiency and Renewable- Energy Revolution It is possible to get electricity from solar cells that convert sunlight into electricity. Can be attached like shingles on a roof. Can be applied to window glass as a coating. Can be mounted on racks almost anywhere.
Core Case Study: The Coming Energy-Efficiency and Renewable- Energy Revolution The heating bill for this energy-efficient passive solar radiation office in Colorado is $50 a year. Figure 17-1
Passive Solar Heating Passive solar heating system absorbs and stores heat from the sun directly within a structure without the need for pumps to distribute the heat. Figure 17-13
Fig. 17-13, p. 396 Direct Gain Summer sun Hot air Warm air Super- insulated windows Winter sun Cool air Earth tubes Ceiling and north wall heavily insulated
Fig. 17-13, p. 396 Greenhouse, Sunspace, or Attached Solarium Summer cooling vent Warm air Insulated windows Cool air
Fig. 17-13, p. 396 Earth Sheltered Reinforced concrete, carefully waterproofed walls and roof Triple-paned or superwindows Earth Flagstone floor for heat storage
Fig. 17-14, p. 396 Trade-Offs Passive or Active Solar Heating AdvantagesDisadvantages Energy is freeNeed access to sun 60% of time Net energy is moderate (active) to high (passive) Sun blocked by other structures Need heat storage system Quick installation No CO 2 emissions Very low air and water pollution High cost (active) Very low land disturbance (built into roof or window) Active system needs maintenance and repair Moderate cost (passive) Active collectors unattractive
Cooling Houses Naturally We can cool houses by: Superinsulating them. Taking advantages of breezes. Shading them. Having light colored or green roofs. Using geothermal cooling.
Wind Wind energy is converted into a usable energy form by using wind turbines www.lacoastpost.com www.windenergyplanning.com
Wind Power Benefits of Wind Power: Readily available Can sell back extra power Pollution free energy source Drawbacks of Wind Power: Disrupts migration patterns Turbine farms are not aesthetically pleasing Turbines are expensive Good for specific locations only
Hydro Hydro power is mechanical energy derived from water Most hydropower is generated by damming rivers Using waves or ocean currents is being researched as a source of hydropower www.southeastasia.biz
Benefits of Hydropower Readily available No pollution produced Constant source of power Drawbacks of Hydropower Damming rivers disrupts ecosystems, causes sediment to build up and disrupts the natural flow of a river
Geothermal Geothermal energy uses natural underground heat sources When heat escapes the earth in the form of steam, the steam is used to turn a steam turbine which converts the heat energy into electrical energy
Benefits of Geothermal: When drilled correctly, little pollution is produced Takes up a relatively small area, does not disrupt the landscape Drawbacks of Geothermal: Can only be used in a limited capacity Very location specific May run out of steam May release hazardous gasses or minerals if drilled improperly
Biomass Biomass is burning biomass fuel in a specialized burner. Steam generated turns a steam turbine which turns mechanical energy into electrical energy
Biomass at the Denver Zoo! Trash and animal waste is converted into pellets The pellets are put into a gassifier and heated to 400 degrees! When hot enough, a gas is emitted that is converted by micro gas turbines into electrical energy Denver Zoo
Benefits of Biomass Less waste in landfills Readily available Drawbacks of Geothermal Not currently available on a large scale basis
USING RENEWABLE SOLAR ENERGY TO PROVIDE HEAT AND ELECTRICITY The European Union aims to get 22% of its electricity from renewable energy by 2010. Costa Rica gets 92% of its energy from renewable resources. China aims to get 10% of its total energy from renewable resources by 2020. In 2004, California got about 12% of its electricity from wind and plans to increase this to 50% by 2030.
Energy Efficiency – renewable energy sources Solar Wind Hydro Biomass Geothermal
USING RENEWABLE SOLAR ENERGY TO PROVIDE HEAT AND ELECTRICITY Denmark now gets 20% of its electricity from wind and plans to increase this to 50% by 2030. Brazil gets 20% of its gasoline from sugarcane residue. In 2004, the world’s renewable-energy industries provided 1.7 million jobs.