Resources & Energy

Resources & Energy Earth Science Spring 2013 Vocab Section 1 Nonrenewable resources- substance of limited supply that cannot be replaced Renewable resources- substance that can be replaced Ores- deposit of minerals from which metals and nonmetals can be profitably removed Veins- narrow band of mineral deposits in rock Lode- deposit formed by thick mineral veins Vocab Section 1 cont Placer deposits- fragments of native metals that are concentrated in layers at the bottom of a stream bed Gemstones- nonmetallic mineral that is brilliant and colorful when cut Mineral Resources Minerals are nonrenewable resources because the processes that form them take millions of years Air, water, and plants are renewable resources and can be replaced within a human lifetime or as they are used Earth scientists have identified over 3000 mineralsProcesses that form minerals take millions of years 4Mineral Resources Formation of OresMost metallic and nonmetallic elements are found in chemically combined forms as minerals in the crust. Minerals are found in ore deposits.Ex: iron is found in magnetite & hematiteEx: mercury is found in cinnabarEx: aluminum is found in bauxite Mineral Resources contOres & Cooling MagmaAs magma cools, dense metallic minerals accumulate and form ore deposits within the hardened magmaEx: Cr, Ni, PbOres & Contact MetamorphismSome ores form through contact metamorphism when hot magma comes into contact with existing rockHeat & chemical fluids from the magma change the surrounding rock Hot minerals spread through small cracks in a large mass of rock & may deposit valuable minerals in veins A large # of thick mineral veins form a deposit called a lode

Mineral Resources cont Ores & Moving Water Movement of water forms ore deposits in 2 ways: 1: Fragments of native metals are released as rocks break down due to natural processes Streams carry the fragments until they are deposited where currents are weak and they become deposited in placer deposits 2: Water dissolves minerals as it flows through cracks in rocks on the earths surface New minerals precipitate out of the solution forming ore deposits called veins Ores of heavy metals often form this way Mineral Resources cont Uses of Mineral ResourcesSome metallic ores are prized for their beauty and rarityEx: gold, platinum, & silverOther metallic ores are sources of valuable elementsSome nonmetallic minerals are gemstones, which are rare crystals cut & used in jewelry because of their brilliance & color Other nonmetallic minerals are used as building materialsEx: calcite & gypsum Mineral Resources cont Mineral Conservation use other more abundant or renewable materials in place of mineralsEx: plastics RecyclingEx: metals like iron, copper, & aluminumEx: glass & building materials Vocab Section 2 Fossil fuels-fuel formed from the remains of living organisms, such as coal, petroleum, & natural gas Hydrocarbons- compound made up of atoms of carbon & hydrogenCarbonization- process in which plant materials are changed into carbonPeat- brownish-black material produced by partial decomposition of plant remainsLignite- brown coalBituminous coal- soft coalAnthracite- hardest form of coal Crude oil- unrefined petroleumPetrochemical- chemical derived from petroleum

Fossil Fuels Fossil fuels are formed from the remains of living things.Contain primarily hydrocarbons Fossil Fuels cont CoalDark-colored, organic rockFormation of coalRemains of plants that have undergone carbonizationCarbonization occurs when partially decomposed plants are buried in swamp mud Bacteria consume some of the plant material & then release marsh gas (CH4 & CO2).As the gas escapes the chemical compounds present in the plants gradually change, and only carbon remains.

Fossil Fuels cont Types of CoalPeat formed from the partial decomposition of plants a brownish black material LigniteFormed when peat deposits are covered by layers of sediment that squeeze water & gases from the peat Brown coal Bituminous CoalFormed from the pressure of more sediments on top of lignite Soft coalMost abundant type of coalAnthraciteForms where the folding of the earths crust produces extremely high temperatures & pressure of bituminous coalThe hardest form of coalBituminous coal & anthracite consists of 80- 90% carbon & produce great heat when they burn Fossil Fuels cont Petroleum & Natural Gas Mixtures of hydrocarbonsFormation of Petroleum & Natural GasRemains of microorganisms accumulated on the floors of bodies of water & were buried by sediment. The sediments limit the available oxygen supply & prevent the remains from decomposing completelyThe heat & pressure become great enough that the remains are converted into petroleum & natural gas Fossil Fuels cont Petroleum & Natural Gas DepositsPetroleum & natural gas form reservoirs when pressure pushes them up through permeable rock. Petroleum & natural gas get trapped below layers of impermeable rock, often called a cap rockUses of Fossil FuelsMain sources of energy for transportation, farming, & industryCrude oil- unrefined petroleum Petrochemicals- components of over 3000 productsEx: plastics, synthetic fibers, medicines, tars, waves, synthetic rubber, insecticides, ect

Fossil Fuels cont Fossil Fuel SuppliesCoal is the most abundant fossil fuel in the worldEvery continent has coalIt is estimated that coal deposits will last about 200 years Petroleum75% of the petroleum in the U.S. has already been discovered As much 90% of discovered petroleum in some areas is still in the ground Oil shale Fossil Fuels contFossil Fuels & the EnvironmentThe use of any fossil fuel has a impact on the environmentCause ground, water, & air pollution Oil spillsGas leaksEtc Nuclear Energy VocabNuclear fission- splitting of the nucleus of a large atom into smaller nuclei Nuclear fusion- combination of the nuclei of small atoms to form a larger nucleus Nuclear Energy Nuclear FissionScientists & engineers have developed technology that uses nuclear reactions to produce energy for commercial use based on nuclear fission Nuclear fission is the splitting of the nucleus of a large atom into 2 or more smaller nucleiU-235 is the only naturally occurring element used for nuclear fission Processed into pellets and then put into fuel rods Nuclear Energy cont U-235 Energy is created when a neutron bombards uranium 235 and the nuclei splits releasing heat the heat can be used to turn a turbine that creates electricity Nuclear reactor is used to do this

Nuclear Energy cont Production of nuclear energy has drawbacksWaste products of nuclear fission give off dangerous radiation, which can destroy plant and animal cells & cause harmful changes in the genetic material of living things Waste used to be dumped into the ocean, but now it is stored in on site water pools or in dry casks Low level wastes can be stored onsite or transported to one of 3 disposal facilities in the US Nuclear Energy cont Nuclear Fusion All of the energy that reaches the earth from the sun is produced by another kind of nuclear reaction called nuclear fusionIn nuclear fusion nuclei of smaller atoms combine & form larger atomsEx: Sun hydrogen nuclei are fused to form helium nucleiCan only take place at temperatures above 15 million degrees Celsius Alternative Energy Sources Vocab Solar collector- device for capturing solar energyGeothermal energy- energy contained in and available from water heated by magma or gases within the earth Hydroelectric energy- energy produced by running water

Alternative Energy Sources Solar EnergyConverting sunshine into useful heat can be done in 2 waysPassive system- requires no working partsWindows Active system- involves the use of solar collectorsSolar panels How solar panels workGlass boxes with tubes of water inside & the sun heats the water and the water circulates through the building Photovoltaic cells Convert sunshine directly into electricity Alternative Energy Sources cont Geothermal Energy Water that is heated beneath the earths surface by hot rocks or magma may be used as a heat source Water can be in contact with the hot rocks or magma or may flow through hot rocks Steam may also be used as a heat source We use this by drilling wells to reach the hot water or steam and then it is pumped up to the surface to be used Alternative Energy Sources cont Geothermal Energy ContIn Iceland 80% of the homes are heated by geothermal energy Italy and Japan have power plants using geothermal energy

Alternative Energy Sources cont Energy from running waterHydroelectric energy is energy produced by water running through a turbine that spins and produces power11 % of the electricity in the US comes from thisDams hold back water and the water is channeled through a plant where it spins the turbines Alternative Energy Sources cont Energy from tidesDams are built to trap the water during high tide & release it at low tideThe water spins the turbine of an electrical generator Energy from the wind Wind farms can produce enough energy to meet the electricity needs of entire communities There are only a few places where this is practical Wind doesnt blow everyday so it cannot be relied on as a total alternative energy source