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All Class Notes GEOL1005
Popular in Environmental Geology
Popular in Geology
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Lecture 23 1 Alternative Energy Resources 0 Fossil fuels are the main source of energy used today 0 All other sources of energy alternative energy sources 0 Alternative Energy 2 types 0 Nonrenewable Energy sources where we use up more source material than can be replaced in the same amount of time ex nuclear power and geothermal energy 0 Renewable Source material is replaced as we use it and therefore is available in the same quantities all the time despite how much we harvest Solar power hydropower wind power hydrogen and energy derived from biomass Nonrenewable Resource Nuclear Energy 0 How does it work Production of nuclear energy relies mostly on ssion ie the splitting of atomic nuclei by neutron bombardment The ssion processes causes the split atom to release lighter elements heat and neutrons which in turn strike other radioactive elements releasing more neutrons in a quotchain reactionquot An uncontrolled chain reaction as in the kind used for nuclear weapons results quite quickly in an explosion However sustained or stable nuclear reactions in reactors are used to provide heat for the generation of electricity 0 Nuclear Energy 0 What elements do we use to create nuclear energy All nuclear energy is produced through the element Uranium Three isotopes of Uranium exist in nature 0 U238 993 of natural U o U235 just under 07 natural U o U234 0005 natural U U235 is the only naturally occurring ssionable material and is therefore pivotal in the production of nuclear energy U238 is not naturally ssionable but is quotfertile materialquot because upon bombardment by neutrons it s converted into plutonium239 which is ssionable Lecture 23 2 0 Where do we get the Uranium o Uranium originates in magma and is distributed to the sediment through weathering of igneous rock Natural concentrations of U in the Earth s crust are actually very low In order for Uranium to be mined for pro t we must nd Uranium deposits with concentrations of 400 2500x s natura concentrations These areas are found in three types of deposits Sandstone impregnated with Uranium minerals Veins of Uranium bearing minerals in rock fractures Ancient placer deposits now course grained sedimentary rock 0 Sustainability amp Nuclear Energy 0 Problem Concept of sustainability how well an energy source can provide for our future energy needs without harming the environment Reactors that use U235 as a fuel are NOT sustainable Today 440 power plants supply 16 of the worlds electricity If that nuclear energy using U235 were increased to provide 40 of the present use of fossil fuels all known U deposits were be mined and used up within 30 yrs 0 Solution Our present reactors use U very inefficiently only about 1 of U is used to produce energy The other 99 ends up as waste As a result currently our nuclear reactors are more of waste problem then they are an energy solution Breeding reactors are designed to produce quotnew nuclear fuelquot They take the 99 that is waste in our present reactors and convert it to new fuel plutonium239 which is all used to produce nuclear energy This way none of the initial U is wasted If constructed in sufficient numbers breeder reactors could supply about half the energy presently produced by fossil fuels for about the next 2000yrs Lecture 23 3 Reactor Design and Operation Steam V structure Turbine Containme m 39 39 structure X Cooling tower Figure Mu26a Earth Portrait ofa Planet Ble 2008 WW Norton 8 Company inc 0 Risk Associated with Nuclear Reactors 0 Nuclear energy and the possible adverse effects associated with it have been and continue to be the subject of rigorous debate 0 Nuclear ssion uses and produces radioactive isotopes At every step of the nuclear cycle mining transportation processing of U production of energy within reactors reprocessing of nuclear fuel and nal disposal of radioactive waste various amounts of radiation are released into the environment 0 Furthermore since plutonium produced by nuclear reactors can be used to make nuclear weapons terrorist activity and the possibility of irresponsible actions by governments add to the risk that is present in no other form of energy production 0 Finally even though an uncontrolled chain reaction cannot occur inside a nuclear reactor because the ssionable material is not used in high enough concentrations unwanted chemical reaction can produce explosions that release radioactive substances into the environment 0 Although the chance of a disastrous accident is very low it increases with every reactor put into operation Lecture 23 0 Case Study Three Mile Island 0 O O O Occurred March 28 1979 at a power plant located near Harrisburg Penn Malfunction of a valve in conjunction with human errors resulted in a partial core meltdown Although intense radiation was released into the interior of the structure it functioned as designed and only a relatively small amount of radiation was released into the environment Woke up American to the dangerous side of nuclear energy 0 Case Study Chernobyl 0 On April 28 1986 workers at a nuclear facility in Sweden frantically began searching for the source of elevated levels of radiation around their power plant They concluded the leak was not from their facility but was coming from the Soviet Union by way of prevailing winds When confronted the Soviets admitted there had been an accident at their nuclear power plant Chernobyl on April 26 1986 This was the rst notice that the world s worst accident in the history of nuclear power had occurred It is believed that human error resulted in the failure of the cooling system for the Chernobyl reactor Temps in the reactor core rose to 5400 F melting the Uranium fuel Explosions blew off the top of the building over the reactor and res broke out all within the compound producing a cloud of radioactive particles that ew high into the atmosphere 0 Future of Nuclear Energy 0 0 Nuclear ssion may indeed be one of the answers to our energy problems It s use is being seriously evaluated for the future because it is an alternative to fossil fuels that does not release green house gasses and air pollutants into the atm However such a power source comes with a huge responsibility to ensure that it is used for the betterment of human kind not its destruction and that future generations will inherit an environment free of hazardous nuclear waste As such before nuclear power can play major role in energy production such topics as power plant safety decommissioning of power plants and reactors as well as nuclear waste disposal must all be fully evaluated Lecture 23 5 Nonrenewable Nuclear Fusion 0 Nuclear fusion combines the nuclear of lighter elements to form a heavier one The fusion processes releases energy and is the source of energy in our sun and stars 0 From an environmental standpoint fusion is very preferable as there is little radioactive waste and mining and transportation impacts are small compared with those of fossil fuels or nuclear ssion o The fuel for fusion is Hydrogen which is nearly unlimited and therefore can supply us with an unlimited source of energy 0 However although harnessing hydrogen for nuclear fusion is still beyond our technological abilities this energy source is very much under investigation by scientists worldwide and may one day play a signi cant role in energy production Nonrenewable Geothermal Energy 0 What is it Harvesting natural heat from the Earth s interior Resource is vast if only 1 of the geothermal energy in the top 10km of the Earth s crust were captured it would amount to 500x the global oil and gas resource 0 Where do we get it Natural heat production within the Earth is only partially understood We do know however that some areas have a higher heat ow than others and that for the most part these locations are associated with tectonic processes Divergent and convergent plate boundaries are areas where this natural heat ow from Earth is unusually high Therefore it s no coincidence that geothermal power plant locations are primarily in areas of known active volcanism 0 Heat ow in the US 0 Temperature increases with depth below the Earth s surface o It is measured in degreeskm amp is referred to as the quotgeothermal gradientquot 0 The steeper the gradient the greater the heat ow to the surface Lecture 23 How do we harness this energy Hydrothermal Convection Systems A geothermal basin in which a variable amount of hot water circulates o Vapor dominated systems both water and steam Near the surface the water pressure is lower than at deeper levels and water quickly changes to superheated steam which can be tapped and piped directly into turbines to produce electricity Water is boiled off faster than nature can replace it in the same amount of time Not very common 3 have been identi ed in the US the Geysers California Mt Lassen National Park California and Yellowstone Power plant Prodluctiorl turbmes Candenser and wells steaml water injection well Us Natural r recharge I r quotI I f Sediimerltsin Jr quotm l I I l geothermal basm 1 r I 1 t quotr ll I Zone of low hydraulic I conductivity traps vapor 1 t f steam Example aclay I f layer in the geothermal basin I l Vapor 39 quot I I I Igneous xf r rack 39 gt Direction of water flow l Natural recharge of water From rain 2 Hot water produced by Earth processes 3 Steam to production well 4 Steam to turbines to produce electricity 5 Water is iniectecll back into ground Copyright 200a Pearson Prentice Hall lnc How do we harness this energy Hydrothermal Convection Systems A geothermal basin in which a variable amount of hot water circulates 0 Hot water hydrothermal convection systems 20x s more common that vapor dominated in the US Hot water systems with temperatures gt 300 have zone of circulating water that when tapped moves up a zone to reduced pressure where it yields a mixture of steam and water at the surface The water must be removed from the steam before the steam can be used to drive a turbine Lecture 23 can 77 aooooooaollooooaoogo 0009000009 0 0 o 0 90 O Dotil oncoooool o l o a a a 6 l o o o o o o o o o o l o i o o x a o 0 l a o a o 0 a n o a l 0 0 0 i a a a 0 l a 0 o 0 0 00 0 o o a a in I J l39 4 H 04 l 94 n oped o hg o 39 39 39 39 I E o U l 0 a a o o O l 0 o l 39 o o o l r y o o o o o o o a o c J Permeable zone 0 a o o o l39 n 0 n a o o n o n a o n a canoe 700060090060696 1quot p f39xl Xx 39l xquotquotquotquot quotquot39 Its Me n 2 7 I in r I ml Crystallinerocks u x l l H s x I as I s Ill 1 l f l I39JJH x x 1 ixquot K 1quot K kquot I z a z I l l Iquot r 1 J39 l 1 Direction ol waler How i Weller circuloling in geothermal basin 2 Wells pump out woler and steam 3 Turbines in plonl produce electricity 4 Water is injected boclk into bosin Copyright2008 Pearson Prentice Hall Inc 0 How do we harness this energy Groundwater Systems 0 Groundwater at a depth of 100m is 55 F 0 This is warm compared with the air temperature in winter and cold compared with the air temperature in summer 0 Heat pumps can use this temperature difference between the water and the air to heat buildings during the winter and cool them off during the summer by transferring heat between the air in the buildings and the water 0 Used in numerous Midwest and Eastern US locations 0 Env Issues 0 lt than other energy sources but still considerable o No extensive transportation of materials or re ning and there is also very little air pollutant created 0 On site noise gas emissions scars on the land are all problems 0 Produces considerable thermal pollution from hot waste waters which may be saline mineralized or highly corrosive to pipes pumps and other equipment Waste water must be disposed of 0 Can cause ground subsidence through removal of uids as well as heat which will cause the rocks to cool and contract 0 May adversely affect the geysers O 0 Future of Geothermal Energy 0 Viable site speci c energy source At present geothermal energy supplies about 1 of the energy in the US Lecture 23 8 Putting cost aside over a 30 yr period the estimated yield from this resource far exceeds that of hundreds of modern nuclear power plants However it is more expensive to produce electricity from geothermal reservoirs than fossil fuels and the economics will have to equalize before this becomes a popular energy source 0 Renewable Energy Sources 0 Have the following advantages lnexhaustible Associated with minimum env degradation With few exceptions does not use fuel burning and therefore not does add to atmospheric pollution Time necessary to implement the technology is often much shorter than building power plants 0 A primary directive to ensure the success of alternative energy is to match renewable energy sources to sites where the natural resources for that source are of the highest quality 0 What makes them Renewable 0 They are all derived from the suns energy Wind Collectors Solar cells Hydropower Biomass lf assive Photovoltaics 39 Micro small 39 Urloan waste and active 39 Large clam 39 Agriculture l i r Electricity Heat Fuels 0 Homes n3 water or air OAlcohol 0 Inlcllustry 0 Buildings Olflyclrogen 0 Agriculture 0 industry 0 Agriculture l t 9 Produces most electricity from renewable solar energy Rapidlly growing strong poternttol wind and solar are growing at 30 per year Used today important energy source Potentially a very important fuel to transition from fossil fuels 0 Solar Energy 0 Total amount of energy reaching the Earth s surface is huge 10 weeks of solar energy is roughly to the energy stored in all known reservoirs of coal oil and natural gas on earth Lecture 23 9 0 Two type of Solar Energy Passive and Active 0 Passive Solar Energy 0 Architectural design systems that enhance the absorption of solar energy and take advantage of natural changes in solar energy that occur throughout the yr without requiring mechanical power Ex Overhangs in buildings that block high angle summer light but allow low angle winter light to penetrate and warm rooms Ex Mirrors that de ect sunlight onto pools for warming 0 Active Solar Energy 0 Solar Collectors Flat panels consisting of a glass plate over a black background where water is circulated through tubes Solar radiation enters the glass and is absorbed by the black background heating the water in the tubes 0 Photovoltaics technology that converts sunlight directly into electricity 0 Solar Energy Env Problem Requires lots of space 0 Hydro Power 0 An ancient source of energy that has been used as a source of power since the time of the Romans 0 Two types hydroelectric and Tidal Power Hydroelectric 0 Provide 10 of the electricity produced in the US 0 Can be used to generate electrical or mechanical power 0 Most of the acceptable sites for large dams to produce hydropower are already being utilized However micro scale hydrosystems giving energy to individual homes farms or small industries will probably be more common in the future 0 Tidal Power 0 Done by building a oodgate dam across an inlet Water ows into the inlet when the tide rises only to be trapped when the gate is closed After the tide has dropped outside the oodgate the water retained by the oodgate ows back to the sea via a pipe that carries it through a power generating turban Lecture 23 10 o A minimum rise of about 8 meters 26ft is needed for developing tidal power 0 Env Effects 0 Clean power require no fuel burning does not pollute the atm produces no waste and is efficient 0 Price to pay Water falling over the dams may trap nitrogen which then enters the blood of sh expands and kills them just like a scuba diver when they rise too fast Nitrogen has killed many migrating game sh in the Paci c NW Dams trap sediment that would otherwise be taken downstream to replenish the beaches Dams ood existing habitats one of side and block water ow onto the other side causing adverse changes to river ecology and loss of wildlife In the US several dams have been removed and several others are being considered for removal as a result of adverse environmental effects 0 Wind Power 0 Another form of ancient energy production In the past it has been used to propel ships and has driven windmills to grind grain or pump water More recently wind has been used to generate electricity 0 At any particular site the direction velocity and duration of wind might be quite variable depending on the local topo and on the temp difference of the atm between the local area and the region 0 As such prospecting for wind energy is a topographic and meteorological problem 0 Signi cant improvements in the size of windmills and the amount of energy they produce have made them an attractive option in Europe and the US for energy production 0 Wind power is an inexhaustible resource an inexpensive source of energy production and clean source of electricity 0 For these reasons wind power is the fastest growing energy resource in the world 0 Env Problems 0 Windmills are responsible for killing many birds 0 Require large areas 0 May degrade area s scenic resources Biomass Fuel Lecture 23 11 Oldest fuel used by humans wood burning o Essentially the burning of organic matter such as plant material and animal waste Ex rewood Ex Cattle dung cooking in India Ex Peat compressed dead vegetation heating and cooking fuel in northern countries 0 Energy from biomass can be generated via several routes Direct burning of biomass to produce electricity or to heat water to air Heating of biomass to form a gaseous fuel through a processes known as gasi cation Processing of biomass to produce biofuels such as ethanol methanol and methane 0 Primary source of biomass fuel in NA are forest products agriculture products and combustible urban waste Manure from livestock and other organisms can be used to form methane and then burned to produce electricity or used in fuel cells This is highly preferable than allowing it release the methane in to the atm o Presently only about 1 of the nations municipal solid waste are being recovered for energy If however all the plants were operating at full capacity and the plants under construction were completed and fully operational 10 of the countries waste 24 million metric tonsyr could be used to extract energy 0 In western Europe a number of countries now use 13 12 of their municipal waste for energy production 0 Env Problems 0 Emissions of air pollutants 0 Production of Ash 0 Has a potential to be a part of the overall alternative energy plans for the future but does not provide enough energy to be a locations only energy source 0 BioFuel Ethanol 0 Made by fermenting and then distilling starch and sugar crops maize sorghum potatoes wheat sugarcane even cornstalks fruit and vegetable waste Env Problems 0 Increased use of fertilizer to keep up with demand 0 Sky rocketing food prices because there is not enough supply for both food and energy Famine in poor countries Lecture 23 12 0 Bottom Line 0 We must become used to idea that there will always be uncertainty concerning the availability cost and env effects of energy use 0 Furthermore we can expect that serious social economic and political shocks will continue to occur disrupting the ow of energy in various parts of the world 0 As such the best way to compensate for the uncertainties described above is to develop a series of energy sources that incorporate quot Conservation Ef ciency and Cogenerationquot 0 Conservation refers to modernization of our energy demand so that we minimize the amount energy necessary to accomplish a given task 0 Ef ciency Designing and using equipment that yields more power from a given amount of energy while wasting less energy 0 Cogeneration refers to a of processes that capture and use some of the waste heat produced by power generation and industrial operations 0 Energy Policy for Future 0 quotHard Pathquot quotBusiness as usualquot Involves nding greater amounts of fossil fuel and building larger centralized power plants This is the more comfortable approach as it requires no new thinking or realignment of political economic or social conditions 0 Soft path Suggests energy alternatives that are renewable exible decentralized and env safer than those of the hard path In the US today we consume 90E of energy per year 0 Projections estimate that US energy consumption in the yr 2030 may be as high as 120E or as low as 60E Why the big discrepancy o If we stay on the hard path the high value is more accurate 0 If however we take the soft path which advocates intensive energy conservation and increased ef ciency the annual consumption will be cut in half 0 Lecture 23 0 quotWe do not inherit the Earth from our Ancestors we borrow it from our Children Ancient Native American Pro verb 13 Lecture 1 1 Environmental Geology Our Place in the World Around Us 1 Impact of natural disasters on modern environments I Although volcanic eruptions earthquakes tsunami s etc are a natural and necessary part of Earth s activities they often result in signi cant change to the local environment and sometimes can affect Earth on a global scale We cannot prevent these changes from occurring but understanding how and why these things occur can help us to protect ourselves when they come about and adapt to the changes they produce 2 Impact of human activities on modern environments I Environments on planet Earth have been evolving since day one and have never stopped In the past these changes were natural and done at nature s pace However evolution at present day has a strong participation of human activities which has made evolution deviate from its natural path I How do we classify environmental issues Local scale issues I Small xed sources are easy to disclose curable in a short time periods a few to tens years I Ex Hg disaster in Japan I Ex air pollution Global scale issues I Large occurring on every continent complex sources takes long time periods hundreds to hundred thousands years to cure I Ex Ozone depletion Ex Global Climate Change I Deforestation and loss of biodiversity Both natural events and anthropogenic processes affect the environment we live in Why so much more concern over anthropogenic affects Natural Changes l Mostly local affects l Takes place over periods of 1000 s of years I Nature knows how to handle her own mess I Out of our control Manmade Changes I Has many local and global affects l Takes place on the order of 10 100 s of years I Nature has no protection against our mess I Within our power stop Impact of natural disasters on modern environments Lecture 1 El Learning to live with Volcanic Eruptions Earthquakes Tsunamis Hurricanes Landstes Flooding ETC VVVVVVV Impact of human activities on modern environments VVVVVVVV Air and Water Pollution Water Depletion Resource Depletion Global Climate Change Waste Disposal Problems Energy Issues ETC Volcanoes Why are some Beauty and others the Beast Lava Beauty Ash The Beast Earthquakes Earthquakes don t kill people Buildings Do Tsunamis Why so different from a Wave Landstes Flooding Red Tides Did I cause that Coral Bleaching Why Costal development Destructive shing methods Pollution Coral mining Global warming Tourism Bottom Line Increasing world population is the number one environmental problem Events such as earthquakes volcanic eruptions oods and res have been occurring on Earth s surface since long before humans populated it These natural processes become hazardous when human beings live or work in their path As such the event itself is not a hazard but a process that becomes a hazard when it threatens human interests Lecture 1 3 l Humans always have and must continue to take advantage of Earth s resources in order to survive I Challenge Accomplish quotSustainabilityquot reach an equilibrium with nature I Understanding the Earth s system and the rates of change in the various components is critical to solving environmental problems Lecture 16 Air Pollution o The Atmosphere Thin envelope of gases surrounding the Earth 0 Troposphere Responsible for meteorological phenomena 0 Stratosphere Contains most of Earth s ozone Mesosphere amp Thermosphere o Exosphere Transition from earth atmosphere to outer space vacuum 0 Chemically 78 N2 21 02 09 Ar rest are greenhouse gases 0 0 Air Pollution What is it 0 Chemical pollutants are compounds that are either In the wrong place at the wrong time ex ozone Present in abnormal concentrations 0 As long as pollutants are dispersed or degraded rapidly relative to its rate of production there is no problem 0 Once pollutants are added to the atm at a faster rate than nature can disperse or degrade them air pollution becomes a problem Whowhat gets affected 0 Peopleanimals and plants Nation wide air pollution results in 300000 deathsyr and 50 billion in healthcare costs 0 Human Artifacts Buildings and monuments suffer discoloration erosion and decomposition of structural materials 0 Aesthetic Effects Discolors the atm Reducing visual range and atmospheric clarity Sources of Air Pollution o Stationary Sources Point sources Fugitive Sources Area Sources 0 Mobile Sources 0 Types of Air Pollutants 0 Primary Lecture 16 2 Emitted directly into the air 0 Secondary Produced when Primary pollutants react with normal atmospheric compounds 0 Carbon Monoxide o Colorless odorless gas 0 Extremely toxic to all forms of life at low concentrations Hemoglobin in our blood absorbs CO 250x more rapidly than 02 Lack of 02 results in asphyxiation 0 Effects of CO toxicity Dizziness amp headaches a death 0 Sources of CO 90 in atm from natural sources 10 form res automobiles and other incomplete burning of organic compounds Volatile Organic Compounds VOC s 0 Include a wide variety of organic compounds used as solvents in industrial processes such as dry cleaning graphic arts and adhesives Hydrocarbons a group of VOC s made of H and C Ex methane CH4 propane C3H8 0 Effects Numerous as they are toxic to plants and animals contributes to photochemical smog 0 Sources 15 anthropogenic on a global scale In the US 50 are anthropogenic Automobiles most common anthropogenic source Produced in signi cant quantities by Biology Nitrous Oxides NOX o Emitted in several forms 0 Light yellow brown a reddish brown gas with an irritating odor 0 Main pollutants contributing to photochemical smog 0 Effects eye nose and throat irritation increased susceptibility to infections suppression of plant growth and damage to leaf tissue impaired visibility through the creation of smog and production of ozone at the surface N02 light NO O 0 Almost all atm nitrous oxides are emitted by anthropogenic sources 0 Ozone at the surface results in damage to rubber paint amp textile as well as destruction and death of plants and Lecture 16 harmful eye and respiratory problems in animals and humans Sulfur Dioxide 502 o Colorless odorless gas 0 30 converted to 04 ne particulate and deposited on Ea h o Oxidizes to form sulfuric acid Main pollutant contributing to sufurous smog 0 Effects paint and metal corrosion plant injury and death when present in 504 form can cause severe lung damage in humans and animals 0 Major source is burning of coal and various other industrial processes 0 0 02 and Acid Rain Battery acid pHE1 Orange 7 Relative acidity hydrogen ion concentration 13121110987654321 Figure 1818 The pH scale is a logarithmic one small differences in pH value translate into large differences in acidity Range of acid precipitation is compared with typical pH values of common household substances 0 Other Hazardous Gases 0 Truck and train accidents regularly release gaseous toxic chemicals in to the atm o Gaseous air pollution from sewage treatment plants 0 Australia Dec 10 2007 THE Gateway motorway was closed in both directions yesterday after 900 liters of the toxic chemical potassium hydroxide solution spilt from a truck in peak hour traffic Lecture 16 0 June 23 1989 LEAD A truck carrying two tanks of toxic chemicals overturned on a pier at Port Newark near Newark International Airport last night causing the Secret Service to change President Bush39s travel plans officials said 0 Jan 31 2008 Johannesburg Two truck trailers containing ammonium nitrate began to smolder on the N3 south on Thursday forcing metro police to close off the highway Ekurhuleni metro police said Particulate matter 0 Small particles of solid or liquid substances Smoke soot dust airborne asbestos small particles of heavy metals 85 emissions into the atm are from natural sources Deserti cation volcanic eruptions res modern farming burning of crop residue and fossil fuels and industrial processes all put particulates into the air 0 Effects of Particulates O O 0 Limits visibility that can results in car and plane crashes Particles can get lodged in the lungs producing chronic respiration illnesses Dust may settle on plants interfering with their absorption of C02 and release of H20 Kill off whole species in the area resulting in a broken food chain and malfunctioning ecosystem Block sunlight which can result in climate change and rearrange the whole biosphere Particulates in the US are believed to contribute to 60000 deathsyr Some close to home examples Soot O Factories using coal instead of clean oil 0 Some close to home examples asbestos 0 Good insulator Some close to home examples Lead 0 When do the pollutants cause pollution Lecture 16 Air pollution is not distribute normally throughout the world it is concentrated in and around urban areas compliments of automobiles and heavy industry When the rate of pollutants exceeds the rate of transport or chemical transformation dangerous conditions develop Several factors determine the rate at which pollutants are concentrated or transported away from their sources or converted to harmless compounds Rate of pollutant emissions Distance that an air mass moves through urban air poHqun Average wind speed Topography inversion layer Height of the mixing layer Inversion Layer u Descending warm air EIevolion Sea breeze h I39 Temperature H Elevation 7 Temperature 7 l l Copyright 2008 Pearson Prentice Halli Inc 0 How pollutants get concentrated 0 As wind velocity increases and the mixing layer gets higher less potential for air pollution Chimney Affect 0 As the emission rate and the downwind length of the city increases the greater the potential for air pollution Lecture 16 6 Distance column rnoves ihrouglh urban area I A V lnversioh layer 7 column I39 r 1 Wind velocity Copyright is 2008 Pearson Prentice Hall Inc 0 Smog Production 0 smog a smoke fog a visible air pollution o If there are a large number of sources contributing to air pollution over a wide area there is the potential for the development of smog o 2 kinds Sulfurous Smog and Photochemical Smog Types of Smog o Sulfurous Smog quotLondon type smogquot or quotgray airquot Primarily produced by burning coal or oil at large power plants Sulfur Oxides particulates Lecture 16 Burning coal or oil in an urban area Releases Sulfur oxides SCx mostly sultur dioxide 5le Particulates with stagnant stable air sutticient relative humidity Cloud cover Formation at inversion layer and thick tog lasting several days Concentrated qr sullurous smog gray air Copyright 2008 Pearson Prentice Hall inc 0 Types of Smog o Photochenical Smog quotLAtype smog or quotBrown airquot Forms by complex reactions between nitrous oxides hydrocarbons and solar radiation Primarily from automobile use Lecture 16 8 Solar radiation in turlbon dried with presence of on inversion layer trapping polllulonfs Organic compounds hydrocarbons Concentrated photochemical smog brown oirl NO nii39lerQIEn oxides Copyright ZUHB Pearson Prentice Hallll Inc 0 Future of Air Pollution 0 Despite the fact that there are many more vehicles and factories than ever before in recent years data from major US metropolitan areas has shown a decline in the total number of days categorized as unhealthy However some major cities like LA and NYC still have unhealthy air much of the time o This is believed to be the result of making cars that are more environmentally friendly burning less and cleaner coal and treating waste gases from power plants prior to release 0 Cities or countries with burgeoning populations and poverty are particularly susceptible to air pollution Controls on Air Pollution Reducing or Replacing harmful materials Collecting capturing and retaining pollutants before they enter the atm A Control of Particulates B Control of Automobile Pollution Lecture 16 9 C Control of 502 0 Control of Particulates o Particulates emitted from stationary sources are much to easier to control than those emitted by mobile sources 0 Large power plants use settling chambers to lter out the particulates o Fugitive sources require measures that will prevent the area from being eroded by wind 0 Watering of dusty roads planting vegetation to inhibit erosion of soil covering debris piles with plastic material 0 Control of agricultural burning is a serious problem 0 Control of Automobile Pollution 0 CO NOx and hydrocarbons are best controlled by regulating automobile exhaust 0 Once these are controlled secondary ozone pollution will decrease as well 0 Other ways to promote reducing automobile exhausts o Require that vehicles be tested each year and have fees be assessed on the basis of results encourage people to buy cars that pollute less 0 Develop and use a cleaner fuel 0 Require new cars to have increased fuel efficiency 0 Control of 502 0 Change from a high sulfur coal of a low sulfur coal 0 Washing relatively high sulfur coal which allows the pyrite to settle out 0 Coal gasi cation converts high sulfur coal into a gas removing the sulfur in the process gas much cleaner than coal 0 Power plants can remove 02 from the emitting spoke through a process called scrubbing 0 Clean Air Act of 1970 0 Objective was to improve the nations air quality 0 Amended in 1977 and 1990 o 1990 amendment Tightens controls on air quality Place extremely stringent controls in the emission of 02 produced by power plants Demanded these emissions be reduced by 50 by the year 2000 and they were Lecture 16 10 Provides a system of allowances that can be sold on the open market Required a reduction in NOx emissions Regulates toxins that are believed to have the most damaging affect on human health Including known carcinogens goal is to reduce these emissions by as much as 90 0 Monitoring Air Pollution 0 Air quality is reported as being good moderate healthy unhealthy very unhealthy or hazardous o Derived from monitoring 5 major pollutants o Particulates 502 CO 03 and NOX o Controlling Air Pollution 0 Currently billions of dollars are spent annually in the US in an attempt to control air pollutants o The money is dedicated to Reducing emissions from stationary sources Reducing emissions from motor vehicles Developing efficiency and conservation measures 0 The 1990 Clean Air Act Amendments drastically impacted American society and industry which includes increases in the cost of many industrial products and services like automobiles and gasoline o The cost and bene ts of air pollution control are controversial subjects 0 In the end best reduce air pollution below a certain standard Lecture 12 1 Coastal Processes Intro to Coastal Hazards o Coasts are extremely dynamic environments in which continental and oceanic processes converge producing landscapes that are characteristically capable of rapid change 0 The impact of coastal processes is considerable because many of our most populated areas are located on the coast It in the US it is expected that most of the population will eventually be located along the nations 150000km 93000 mi of shoreline including the great lakes Today the nations largest cities lie in the coastal zone and 75 of the population lives in coastal states 0 The most serious coastal hazards are as follows 1 Rip currents generated in the surf zone 2 Coastal erosion which continues to cause considerable property damage that requires human adjustment 3 Tropical cyclones called hurricanes in the Atlantic and typhoons in the Paci c 4 Tsunamis Coastal Processes Waves 0 Waves that batter the coast are generated by offshore storms o The size of the wave produced depends on the following Velocity of the wind Duration of the wind Distance the wind blows across the surface or fetch 0 Basic shape or quotwave formquot of waves moving across deep water are determined by Wave height Distance between a waves crest and trough Wave length Distance between successive crests Wave period The time in seconds for successive waves to pass a reference point Foreshore Backshore 7 zone intertidal zone c rm Beach ME ix Begg ae quot a7 39 39 cuff Iquot face I S Wf 7 Dome Mann I T f l i Q Berm x h g Shoalilng Said I 7 deposited 39I i I yr lmact ive r sand Wave touclltes 39 bottom Wave base Figure 1l B l 9a lEairthi Portrait of a Planet Sale 2008 WW Norton 8 Company llmc Lecture 12 2 o How much energy is expended The amount is surprisingly large Waves with a height of 1 meter hitting a 250mi open coastline over a given period of time is equivalent to the energy produced by one average sized nuclear power plant over the same period of time Waves and Topography o Waves are designed to atten out coast lines Headlands are sticking out further and they have a steeper sope Embayment Headland Figure 113 20 Ea thortrait of 3 Planet Sle 2005 WW Norton amp Company llnc Waves and Topography Lecture 12 3 Plunging breaker so bathe Spilling breaker I V J slope beachj lb Copyright 2008 Pearson Prentice Hall Inc 0 Coastal Processes Beaches Zone oi longshore 1 sediment transport l quot 747 or Swosh SurlE Breaker Semen or zone zone zone dUhe line Berms Beach che 39 L0n95h0re Longshore Pugh bdr Copyright 2008 Pearson Prentice Hall Inc Sediment Transport along Beach Longshore current and Littoral Transport 0 Major source of sediment to the coastlines are rivers depositing sediments into the deltas and waves pick up sediment and move it along the coastline o Littoral Transport system up washes at an angle and backwashes perpendicular Lecture 12 l Sufi Zone where Ilon gsliore drill occurs in longishore current Swosh zone where beach drill occurs Copyright 2603 Pearson Prentice Hall Inc Hazards Rip Tide Rip current Beach Fi giu I39lE 11321 Earth Portrait ofa Plane 3 6 21105 W Norton amp fompan y Inc Hazards Coastal Erosion 0 Due to global rise in sea level and inappropriate development in the coastal zone coastal erosion is becoming a major problem 0 Coastal erosion is usually a more continuous predictable process then other natural hazards such as earthquakes Lecture 12 5 volcanic eruptions or oods so much time and money is spent attempting to control it o If extensive development of coastal areas for vacation and recreational living continues coastal areas will become a critical problem Erosion Factors 0 Humans Dams and engineering structures 0 Severe storms and hurricanes o Rising sea level 0 Sea Cliff Erosion 0 When a seacliff a steep cliff or bluff is present along a coastline double problems arise because the cliff is exposed to both wave action and land erosion running water and landslides These processes work together to erode the cliff at a greater rate than either process could alone 0 The rate of erosion depends on the resistance of the rocks and height of the sea cliff 0 Much of the erosion that takes places near these seacliffs is natural and very difficult to control 0 Sea Cliff Erosion o Urbanization results in runoff which if not collected and diverted away from the seacliff can induce serious and rapid erosion o Watering lawns and gardens on top of seacliff also increases erosion 0 Large structure near the edges of seacliffs building swimming pools and patios near the edge of the seacliff my introduce instability by adding weight to the slope Beach Budget 0 Input sand supplied from rivers and transported down the beach by littoral transport 0 Output Sand removed from the beach by littoral transport or storms o If lnput gt Output beach grows o If lnput lt Output beach erodes o If lnput Output beach stays the same size 0 Storms short term change in sediment supply 0 Climate change or human impact long term changes in the beach budget Lecture 12 0 Engineering Structures Often cause more problems then they solve After Figure 184131 Earth Portrait of 3 Planet lie 9 2008 W W Norton 8 Company Inc 0 Engineering Structures Sandy beach D Deposition Beach grain barrier 10 longshore clritl constructed of large rock bllocllcs or other materials CopWight 2008 Pearson Prentice Hall inc E Erosion narrow beach 0 Beach Nourishment An Alternative Lecture 12 7 Provides protection against storm attack r Direction of wave movement lD une Beech Nearshore Wave begins to steepen berm zone as it lbegins to Feel bottom 7 7 r yW GVe UMP Breaking wove tittle or i 39 Aon lbor39 39 Deepwmer no surge Erodled neorsitore 5 11 39 77 WGVE i moterioi equais w reg4 r Offshore bar u EXiSimg mmerl i New lbeoclh tillll materiel seowolll 7 l With improvement Prlor to Improvement copyright 2008 Pearson Prentice Hall Inc 0 Hazard Tropical Storms o Cyclones are generated by a substantial pressure gradient on the margin of an air mass low pressure in the middle high pressure on the outside 0 Anywhere a pressure gradient exists winds begin to blow 0 Due to what we call quotthe Coriolis affect these winds will move in a spiral around the air mass 0 Because winds move from high pressure to low pressure winds tend to ow toward the center of a low pressure mass where they converge and create an excess that must ow up rain bands Copyright 2003 Pearson Prentice Hall Ilno Dubai Man Made Islands are Sinking Lecture 12 8 o Manmade Dubai Islands are beginning to sink into the ocean due to natural erosion and the navigational channels between then are silting up 0 Hurricane When Sustained wind speed exceeds 74mihr 0 Hurricanes and Typhoons begins as cyclones 0 Because these storms form over warm tropical waters air that rises within them is particularly warm and moist 0 As the air rises it cools and condenses releasing heat that provides energy to the storm causing the air to rise still higher and developing an even lower pressure in the middle 0 The low pressure interior then sucks up even more warm moist air causing the storm to grow broader and rotate faster 0 Due to years of data collection it is now possible to more accurately predict where a hurricane is likely to hit land and if it will instead go out to sea 0 Hurricanes are ranked from category one smallest storm to category ve largest st yrm 7 1 VJQquot J lg 2139 rk quot 2 m u 7 A UNlTED STATES ATLANTlC OCEAN I k k 1 04 quotr R JLHJNim ex H Q a if Gullr of MEXCO f Mexico 5 II I39 r NJ mg 0 Haza rd Tropical Sto H 0 High Win ds gt HUlri CO 9 Pall soutH AMERICA 0 Flooding from excess precipitation 0 Storm Surge a Most lethal Meteorological phenomena Because of the lower air pressure associated with a storm the water level rises up At high tide can be 33ft small storms can trigger a storm surge of 16ft How do we solve this 0 Build house on stilts or with tunnels underneath to let water ow through if there is as hurricane Lecture 12 line E3o Shoreline Copyright 2008 Pearson Prentice Hall Inc 0 Bottom Line 0 Coastal erosion is a natural process rather than a natural hazard Erosion problems occur when people build structures in the coastal zone Because these environments do have a certain amount of natural erosion the best land uses are those compatible with change 0 Any shoreline construction causes change The beach environment is dynamic and any interference with those processes is likely to have adverse consequences Lecture 17 1 0 Global Energy Balance The atmosphere s role 0 The Earth is suitable for life largely because of our temperate climate 0 Earth is the only planet in out solar system with temperatures that allow liquid water at it s surface 0 Avg Venus surface temp 8609F can melt lead Avg Mars surface temp 679F Avg Earth surface temp 599F Weather or Climate 0 Weather Refers to the state of the atmosphere at a given time and place Changes from hour to hour and day to day 0 Climate Average state of the atmosphere in a given region over long periods of time Climate data cannot predict weather 0 quotClimate is what you expect but weather is what you getquot 0 How do we describe Earth s weather and climate 0 Elements are very interrelated as a change in one often produces changes in others 0 Quantity and properties of the following elements are what are measured and used to describe the state of the atm 0 Air temperature Humidity Type and amount of cloudiness Type and amount of precipitation Air pressure Speed and direction of wind 00000 0 What Drives Earth s Weather and Climate o lnsolation over the Globe 0 Earth Sun Relationships 0 Tilt of Earth s Axis Lecture 17 lnsolatlon over the Globe 1 unit quot P 1 1 unlt 14 units Copyright 2003 Pearson Prentice Hall Inc o w Id D t b t fT OI IS Fl U Ion O empera ure 39 1 Suhai39ctic zone Much of the subarctic zone is com The Earth39s diverse environments lay latitude e red hy evergreenlf rest FIGURE 2 B seen here with a ground cover of snow Neat 39Chuinchill Hudson Bay rem gluonI Canada Latitude scale Latitude mnes Mldlatitude zone A pmpnnmnal to area Nu h pular summer midtatltudet Q ifm c landscape in the Tue can re ion email Midlatitude y g Y Subtropical Tropical Equatorial Tropical zone The 7 I tropical zone is the Tmp39w home of the39world39s 39 Subtropical d rie wese39t Piquot tuted here i5 Rub39 al 50mm 1 M dmmde Khalil Saudi Arabia 39 L 39 Subanterclic l Antarctic l South polar Warlcl latitude zunes A geographers system of latitude zones based on the seasonal patterns of daily insulation Equatorlal 2913 An gheerved ever the globe eq39uatd rlal reinforest as seen alonga strearn in the Gun ng39 Palung Natldnal Park Borneo Indanesie o E th s 39 39 ar un Relationships Lecture 17 3 Orbit of the Earth Around the Sun FIGURE 1 1 9 WW39WHE39Comquot golle elslrahler TheEa hSormtammndtheSunlsnotquheckcmanbut lsm the shape of an ellipse As a result the distance between the Sun Vernal equinox and the Earth varies with the time of year mamh 21 Summer solstice June 21 39 Aphelion quot C Juli4 l 15 9 th1 Pe he on 147000000 km Jan 3 i r r g s i a i i 945 01 00quot mi 915004500 mi f Center of enipse Focus of ellipse Winter solstice Dec 22 Autumnal equinox Sept 23 o Tilt of Earth s Axis 0 Makes an angle of 665 from the horizontal ecliptic plane and 235 away from the vertical 0 Rotational axis remains pointed toward Polaris North Star 0 Direction of the axis does not change as Earth revolves around the sun Earth39s or 0 Revolution Tilt of Axis 0 Seasons and hours of daylight change throughout the year because Earth s axis tilted instead of perpendicular to the plane containing Earth s orbit around the sun plane of ecliptic Lecture 17 4 Equinox and Solstice Conditions 24 hour 1 night 25 ho urvday 39 rArctic Circle 439 W i5ubsn lar l39 N igh39l point quot 24hour day3 39 24hnimr 7 Antarctic Circle night Summer solstice Winter solstice 0 Daily Insolation Measures the ow of solar power available to heat the Earth s surface 0 Most important factor in determining air temperatures 0 Variation in temperature at a given latitude throughout the year caused by Suns vertical rays migrating toward and away from a place during the year 0 Single greatest cause for temperature variations is differences in receipt of solar energy Variation in temperature from one latitude to another caused by 0 Variations in the angle the sun s rays hit the planet 0 Length of daylight 0 World Distribution of Temperature daily insolation o The change in daily insolation with the seasons at any location is therefore a major determinant of climate 0 Why is Earth just the right temp 0 Greenhouse Effect 0 Greenhouse Effect 0 Trapping of heat in the atm by quotgreenhouse gasesquot water vapor carbon dioxide methane and CFC s Let s Start at the Beginning Lecture 17 5 0 Earth receives energy from the sun and emits energy back to space in the form of electromagnetic radiation 0 Electromagnetic radiation is emitted by everything having a temperature above absolute zero 0 Properties of Electromagnetic Radiation 0 Self propagating wave that is similar to a wave that moves on the surface of a pond 0 Moves at a xed speed C Le the speed of light 3 x 108 ms in vacuum 0 Wave consists of a series of crests and troughs o The distance between the two adjacent crests wavelength A 0 Frequency u the number of crests that pass a stationary observer in one second 0 Properties of Electromagnetic Radiation 0 These 3 characteristics speed wavelength and frequency together de ne the behavior of a given wave 0 Mathematically the relationship is as follows Auc 0r uC o The longer the wavelength the lower must be the frequency The shorter the wavelength the higher the frequency 0 The Electromagnetic Spectrum 0 Full range of electromagnetic radiation 0 Divided up based on the differing wavelengths o Wavelengths are measured in nanometers nm or mm o The shorter the wavelength is the higher the energy is Spectrum of sunlight 50 visible light 40 Infrared 10 Ultra Violet o A little visible light lesson 0 When you look at an object the color you see is the color of light either emitted or re ected off it 0 Within this range the color of light depends on the size of the wavelength Lecture 17 6 o Longest visible wavelengths appear to our eyes as red whereas the shortest wavelengths appear to our eyes as blue to violet o In the atm this occurs due to a process called scattering o quotSelective Scattering when certain particles are more effective at scattering a particular wavelength of light 0 Aerosol soot water droplets and dust are larger and scatter all wavelengths of light 0 Gas molecules are smaller and scatter only short wavelength light blue violet 0 Why is the Sky Blue 0 Because of Scattering o All visible light mixed together white light When small gas molecules scatter light it re ects the shorter wavelengths blue and violet making the sky blue White light blue light yellow sun On a cloudy day the sky appears white because the presence of larger molecules in the atm like water droplets scatter everything If the cloud cover is so bad light can t really get through gray While the sun is shining through a thin layer of atm as it does during the day the small amount of blue and violet light scattered by the atmospheric gas molecules makes the sky blue 0 When the sun is rising and setting the sunlight must go through a much thicker amount of atm In this case almost all the blue light is scattered back into space 0 White light lots of blue red sky 0 Red sky during the day lots of pollution in the air NOT GOOD 0 Earth s Temperature is dependent on 3 things 0 The amount of sunlight Earth receives 0 The amount of sunlight Earth re ects o Atmospheric retention of reradiated heat 0 Where does the atm come in How much does our atm do for us 0 If our atmosphere did not contain gases that are capable of trapping and retaining heat the average surface temperature of the Earth would be 59 F below the current one or 0 F Lecture 17 7 o This warming is a direct result of the greenhouse Effect 0 What is the Green House Effect 0 Certain gases in the atmosphere are known as quotgreenhouse gassesquot 0 With minor exceptions this means that They readily transmit solar radiation allowing the sunlight to penetrate to earth relatively unimpeded They readily absorb terrestrial radiation thus making it more difficult for this energy to escape to space 0 The quottrappingquot of terrestrial radiation means that there is more energy retained by the earth and its atmosphere leading to a planet which is warmer than it would be in the absence of the atmosphere 0 How does the greenhouse effect work 0 The sun can be expected to radiate shorter waves than Ea h The greenhouse gasses in our atm are designed to absorb IR radiation not visible light Therefore the sunlight emitted as visible light comes through the atm virtually unimpeded whereas the IR radiation re ected back from Earth gets absorbed by the green house gasses and in affect warms our planet 0 Remember the higher the energy the shorter the wavelength As such hotter bodies emit radiation at shorter wavelengths than do colder bodies 4 Reluliwely shortwave radialion Relcllively longewave radlulion 7 22 VL from Sun mosin visible From Earth mostly infrared Peaks in the visible light Radialion llux speclra 0 million 106 limes greater lhon lhe or 1 9 Earth 39 I l l I 00 01 l0 l0 H10 1000 Wavelenglh pml gt Copyright 2008 Pearson Prentice Hall Inc 7 Bending mode I 1 5quotle band Lecture 17 8 o What is a greenhouse gas A molecule able to absorb or emit IR radiation 0 Rotation slow more spread out o Vibration takes low energy to make it berfd L o Rotation fast momentum conserved g o Vibration Takes high energy to bend gt I Flotation Vibration What are Earth s greenhouse gases 0 Water vapor and C02 are the most important greenhouse gases in the atm 0 Between these 2 gases virtually 100 of IR radiation above 12pm and much of the radiation from 1 12pm as well 0 Several other gases like CH4 N20 and CFC s also make contributions to greenhouse warming 0 Global Energy Budget 0 Perfectly balanced such that Earth s temperature stays within the limits of natural variability UNLESS WE DISRUPT IT 0 Global Temperature Change 0 Earth s temperature has by no means been stable 0 Recent Global Climate Changes 0 In the last 100yrs global mean annual temperature increased by 14 F Most of the increase has been since the 1970 s 0 The 1990 s and the rst 5 years of the 21st century had the warmest temperatures since global temperatures have been monitored quotlate 20th century increase in global temperaturequot 0 What sets this time period apart 0 Evidence for Global Warming Lecture 17 TABLE 192 Evidence Supporting the Late TwentiethCentury Rise in Global Temperature Global Temperature Data from the United States NCAA and Europe WIVIO Warming since the mid19705 has been about three times as rapid as the preceding century The 1990s was the warmest decade in the last 142 years and the last 1000 years from geologic data The 10 warmest years have all occurred since 1990 and the five warmest since 1997 The warmest year on record was 2005 with 1998 second and 2002 and 2004 tied for third In 2003 the United States was cooler and wetter than average in much of the eastern part of the country and warmer and drier in much of the west Ten western states were much warmer than average Nlew Mexico had its warmest year Alaska was warmer in all four seasons and had one of the 5 warmest years since Alaska began taking measurements in 1918 Europe in 2003 experienced summer heat waves with the warmest seasonal temperatures ever recorded in Spain France Switzerland and Germany Approximately 15000 people dliedl in heat waves in Paris during the summer Warm conditions with drought in 2003 contributed to severe wildfires in Austrlia southern California and British Columbia Canada Note A few years of high temperatures with drought heat waves and wildfires are not by themselves an indication of longerterm global warming The persistent trend of increasing temperatures over several decades is more compelling evidence that global warming is real and happening Copyright 2008 Pearson Prentice Hall Inc 0 Why does Global Climate Change 0 0 We now believe that our climate is inherently unstable and capable of changing from one state to another in as short a time as a few decades The following variables are thought to cause changes to the climate system Milankovitch Cycles Ocean Conveyor Belt Solar Variation Volcanic Eruptions Us Milankovitch Cycles 0 O O The collective effects of changes in the Earth39s movements upon its climate The Earth39s axis completes one full cycle of precession approximately every 26000 years At the same time the elliptical orbit rotates more slowly The combined effect of the two precessions leads to a 21000year period between the astronomical seasons and the orbit In addition the angle between Earth39s rotational axis and the normal to the plane of its orbit obliquity oscillates between 221 and 245 degrees on a 41000year cycle It is currently 2344 degrees and decreasing Lecture 17 a b 10 Ocean Conveyor Belt Sinking U pwellling Cold and salty deep current J Copyright 2008 Pearson Prentice Hall Inc Solar Variability amp Volcanic Eruptions o Suns energy has been know to vary 0 Medieval Warm Period corresponds with a time of increased solar radiation comparable to that which we see today 0 Minimum solar activity coincided with the beginning of the 14th century Little Ice Age 0 Affect is relatively small there was only a 25difference in solar energy between the Medieval Warm Period and the Little Ice Age Anthropogenic Sources Volcanism o 06Gtyr of carbonate rocks are released into the atm through volcanism o Carbonate rock reservoir exerts very little in uence on the carbon cycle Respiration photosynthesis o CHzO 02 a C02 H20 respiration 0 C02 H20 aCH20 02 Photosynthesis o GOGtyr of carbon go into the atm and 62SGtyr cycle out 0 Another ZGt are added to atm through deforestation 0 net difference is an extra OSGt of output Oceanatmosphere interactions Atmosphere directly interacts with ocean surface passing 92SGtyr to the surface and getting QOGtyr back Net difference is an extra 2SGt of output Combustion 0 Burning of fossil fuels 0 Putting 6Gtyr of carbon into atm Total Lecture 17 11 o 6 06 input 25 5 output 36 Gt accumulationyr in atm C02 remains in the atm for 4 yrs before being removed by one of the above processes 0 How much are we adding 0 Measurements of C02 gas bubbles trapped in Antarctic ice sheets suggest that during the past 160000yrs the atm concentrations of C02 has varied from 200ppm 300ppm 0 At the beginning of the industrial revolution the atmospheric concentration was 280ppm 0 Today concentrations are gt 370ppm and are expected to reach 450ppm more than 5 x preindustrial levels by 2050 o Is the current warming trend our fault orjust nature taking its course 0 A recent mathematical modeling study determined that the level of natural variability in the climate system over the last 1000 years cannot explain the warming that has occurred at the end of the 20th century 0 In other words present warming greatly exceeds natural variability and clearly demonstrates that anthropogenic activities are signi cantly contributing to this latest spell of global warming A 2000 report from the international panel of climate experts concluded that although uncertainties do exist there is suf cient evidence to state that 1 There is a discernable human affect on global climate 2 Global warming is now occurring 3 The mean surface temperature will likely increase from 15 6 C 26 102 F during the let century Effects of such warming 0 Shift in climatic patterns 0 Melting of ice caps Climate Pattern Changes 0 Natural Disasters Will increase the frequency and intensity of storms Drastically increase the problem of drought res and water resource 0 Rearrangement of the biosphere 0 Agriculture Lecture 17 12 Global rise in temperature will signi cantly change rainfall patterns soil moisture relationships and other climatic factors important to agriculture 0 Animal Pyramid Food chains will be interrupted Bleaching and redistribution of the coral reefs Sea level Rise Melting of the Ice Caps will cause a major rise in sea level o If all icecaps melted sea level would rise 250ft o 20 of the worlds land area would be submerged o Alter the ability of streams to easily drain into the ocean causing major ooding within the continents o 16 inch rise in clevel would greatly increase coastal erosion making beach front buildings more vulnerable to wavesand allow landward migration of existing estuaries How can we x this We have got to decrease the amount of C02 entering the atm 0 Reduce Fossil fuel use and nd alternative energy resources 0 Create a C02 sink so that the C02 is not released into the atm 0 Bottom Line 0 Yes nature maybe causing some warming but it has been mathematically demonstrated this warming trend falls outside the limits of natural variability 0 As such even if we are not directly causing it we are drastically aggravating the situation 0 Its time to nd a new cleaner source of energy Lecture 2 1 Earth System Components and Dynamics 0 System a group of components that interact with each other 0 Four components in Earth s system 1 Hydrosphere a The water environment on Earth CIomdl Formation Raina glands P reci pl 1ch lie n Copyirighl l 2003 Pearson Prentice Hall in 2 Biosphere a Estimates range from 2 million 100 million species b To date about 21 million species that have been classi ed primarily in the habitats of the middle IaUtudes c Biological life is intricately woven into Earth s Cycles i They responsible for converting sand and silt into soil ii They regulate ocean chemistry iii Remove C02 from the atmosphere and replace it with oxygen 3 Atmosphere a Thin envelope of gases surrounding Earth b Troposphere i Responsible for meteorological phenomena c Stratosphere i Contains most of Earth s ozone Mesosphere amp Thermosphere e Exosphere P Lecture 2 i Transition from earth atmosphere to outer space vacuum f Chemically 78 N2 21 02 09 Ar rest are greenhouse gases Lecture 2 Ii g l Strain 1 1L I Tropo phem Eloud r l I 1 100 30 E60 40 20 0 20 40 60 Temperature C Copyright 2008 Pearson Prentice Hall Inc Lecture 2 Less dense 39 1 k Denser a Gravit in 139 lllllllllllllm Figure 25 Earth Portrait ofa Pianet Elle 2 03 WW Norton 8 Company lot 4 Lithosphere Inner Earth Comprises crust and top part of the mantle Has a layered structure based on density of the rock Crust 2 types 0 Continental crust 35 km Granitic o Oceanic crust averages 5 km Basaltic Moho Crustmantle boundary marked by a sharp increase in seismic wave speed Upper mantle 7O 400 km Consist of three types of rocks igneous sedimentary and metamorphic o Asthenosphere Slushy layer that the lithosphere oats on Lecture 2 o MiddleLower mantle dense ultrama c rocks 0 Liquid outer core Fe and Ni 0 Solid inner core Fe and Ni 0 As you go from Crust a Core 0 Pressure amp therefore Density T Makes things more solid Temperature T Makes things more liquid Constant battle between the two throughout the Earths interior Sea level Marine sediment Mohorowri i discontinuity Oceanic crusl OOOO 0 AVERAGE DE NSITY gramquot m k i 7 lesenii tstyii Aslhenosplhere 77 Copyright 2008 Pearson Prentice Hall lino The Rock Cycle Lecture 2 Erosion De 39ositi39on 7 f Depsvifion lgneeus and Igneous racks g mtumorphic rock Dceanic crust continental crust Metumnnphic rack I Sedimean Igneous t rock mck G pxyright Ev EDGE Pearson Prentice quotHall Inc Metamorphic rock Copyright 20GB Pearson Prentice Halt zlncm Ea rth s Beautiful Waltz Lecture 2 7 Geologists Study the Earth Far39nira lrr iirw V precipitatiun cnnrribule in wealhermg cl reeks lEtepcuretien ccnclensalicn 39 Plenll39 animal and human and Immigiiljals l transfer elemlily all cult39lpgllilslillntrl It welcr bclwecm el n icsptlcre atmospheric gases and hytlrecsr here in uencing Al espheric tanccrelure Heel ees l er and clima ie suit creclpllaucn E39Iell lo ctermine distribution at wallet dislrilauticunl cut Eerlh s biela Fflsms ebserlia and Irsnsplre 51th Wales IS LliSEd by gentile ltjr Hart s13h agricultural and inclus39lnrial uses Waited helps detenninc abundance fii i E fEhl39f and distriljlnlicn cll crgxanisms Plate mmernenl eFlecEs wee Urganm e meals exm rock shape and clislritiuticna cl mic sell Peeple alter ring vegan hasln Running waler landscape Platermmxemenl and glaciers El dE rcclu aim etlccts Wulm l and sculpt tantl sceecs distribution of Eerlh39s biota lHEHl re ected lre rn lancl surlecc alteels ier r lperatum iii aimlcsphere lDIs39lIlili39Jutit39jl rl cl rreunttIins alrccls weather patterns quot391m39a lr Shlin chccticnn cells wiltgin manila ur39llnljule u r139IIJ39lE I39Ieni U1 shit15 n lh h mj encl recycling of lil39lltlril 1rrit m l volcanic gases life sustemtatien water chemistry erosion1 A A ll Interactions between individual component maintain a feedback loop 239 Interactions are linked with each other E compiling That is to say you can t isolate the effect of individual stroke from each component 3 Eeclh component is itself a sub dynamic system Natural Gas Fuels are made from organic material that has been transformed by physical and chemical processes after burial Lecture 22 Fossil Fuels CoaLlDH8 O ThelJ consu F055 0 o S is dependent on fossil fuels for virtually all the energy we me Fuels are Messy The environmental disruption associated with the exploration and development of fossil fuels must be weighed against the bene ts gained from the energybut it must be understood that the two come hand in hand Good conservation practices combined with pollution control and reclamation help minimize the environmental disruption but in cannot be completely eliminated Coal How is it formed bl Rise in sea level buries swamp in seclimenl Cool lhiclknESS lc Compression of peat forms cool Coal Classi cation Type based on of carbon and it s heat value of combustion TA B l E 1 4 2 Types of Coall Material Carbon Energy Content Rank Peat 50 1500 keenlin Lignite 70 3500 kcailllkgi Lo warank coal Bituminous coal 85 6500 kcalflkg Midrank coal Anthracite coal 95 7500 kcailflkg Highranlk coal 11 kc al kilocaloiriel 1000 calories A calorie is the heat needed to raise the temperature of 1 gram of water by 1 C 39 kg kilogram 22 pounds Lecture 22 2 0 Coal Classi cation Sulfur content based on concentration of S in the coal TABLE 152 Distribution of United States Coal Resources According to Type and Sulfur Content Low Medium or High For example 97 percent of anthracite is low sulfur content and 43 percent of bituminous coal has a high sulfur content Sulfur Content1 Type lLow Medium High Anthracite 971 29 Bituminous coal 298 268 434 Subbituminous coal 996 04 Lignite 907 93 All ranks 650 150 200 1Low 0 196 sulfur Medium 1 3 sulfur High gt3 sulfur Source US Bureau of Mines Circular 8312 1966 Copyright 2008 Pearson Prentice Hall Inc 0 Coal Distribution in the US Ax R 1 ATLANTlC l G OCEAN ignite x k K C PACIFIC OCEAN re Coal Distribution Worldwide 0 US has about 25 of these reserves 0 Annual world consumption is 5 billion tonsyr At that rate of consumption known reserves are sufficient for 225yrs 0 However countries undergoing intense industrialization like China may cause the reserves to be depleted sooner Impact of Coal Mining 0 Most coal mining in the US is done by strip mining although open pit and underground mining is also used 0 Currently there is 40 billion metric tons of coal reserves that are now accessible to surface mining techniques and another 90 billion metric tons within 165 feet of the surface potentially available for stripping if need demands Lecture 22 Affects of Coal Mining Wetter regions 0 0 Acid mine Drainage Drier regions Damage with no water to repair Underground mining of coal also has produced hazards and resulted in signi cant environmental damage 0 Acid water drainage and Land subsidence Coal res that start in mines and can burn for yrs 0 Future Use amp Env Impacts of Coal 0 Limited resources of oil and natural gas are increasing the demand for coal and the coal industry is planning for increased mining activity 0 This solution to oil and gas shortages will have signi cant affects for several reasons More and more land will be strip mined and will this require careful restoration Unlike oil and natural gas coal leaves behind ash 5 20 of the original coal that has to be disposed of in land Hs Handling of tremendous quantities of coal through all stages mining processing disposal of mining waste shipping burning and disposing of ash has potentially adverse environmental effects such as water pollution air pollution release of trace elements likely to cause serious health problems into the air water and soil and aesthetic degradation at mines power plants and other facilities associated with the coal industry Several billion tons of coal worldwide are burned each yr releasing huge amounts of CO2 into the atm This is one of the main mechanisms by which global warming is thought to be accelerated Environmental problems with coal although signi cant are not insurmountable and careful planning could minimize them As of now there is no clear alternative in sight to mining tremendous amounts of coal so the objective should currently be to nd a way to minimize the environmental damage Hydrocarbons Oil and Natural Gas Hydrocarbons crude oil and natural gas are made up of Carbon Hydrogen and Oxygen Examples of natural gas include methane CH4 ethane propane and butane O O Lecture 22 4 Methane is the most common component in natural gas making up 80 of the energy gases present at any location 0 Oil and gas are found in concentrated deposits which have been heavily mined from wells They are also found in less readily available form in shale and tar sands Number of carbons in the hydrocarbon Product molecule LOW viscosity Natural gas C1 to C4 Bottled gas Gasoline C5 to C10 Kerosene C11 to C13 Heating C14 to C25 oil Lubricating C25 to C49 oil High viscosity Tar gt C4D Figure 39ll43 Earth1lP ortrait of a lP lanet Bile 2003 WW Norton 8 Companyllnc rock it xx asst HHNJJIFH39JH fffflffa39lf b Fuuli lrop cl lUnconiormily trop Lecture 22 0 When oil and gas are impeded in their upward migration by a relatively impermeable barrier or quotcap rockquot they accumulate in the reservoir rock 0 Anticlinal trap Oil and gas will be trapped in the crest of O O the anticline Fault trap Oil and gas are blocked by a fault Unconformity trap Oil and gas are blocked by a buried erosion surface Petroleum liquid hydrocarbon How do we get to it 0 O 0 Production elds in an oil well recover petroleum through 2 methods Primary recovery Uses natural reservoir pressure to move the oil to the well where it can be pumped to the surface Normally this pumping delivers no more than 25 of the total petroleum in the reservoir Enhanced recovery Manipulated reservoir pressure by injection of water steam or chemicals into the reservoir pushing petroleum to wells where it can be lifted to the surface by means of the quothorseheadquot bobbing pumps submersible pumps and other lift methods Increases recovery rate to 50 60 Petroleum production always brings to the surface a variable amount of salty water or brine along with the oil After the water and oil have been separated the brine must be disposed of because it s toxic to the surface environment 0 Natural Gas 0 O O 0 Natural gas is a relatively clean fuel compared with coal and oil and has the potential to replace coal and oil during the transition from petroleum and coal to alternative energy sources Worldwide amount of natural gas is quite large enough to last 1 century at recent rates of consumption Exploration for natural gas in the US is ongoing and considerable new gas is being found and developed One of the main problems a explosive Distribution amp quantity of oil and natural gas Lecture 22 6 Crude all world total 1f87 5 billion barrels Natural gas world total 64843 trillion cubic feet Saudi Arabia Chin a C anada United 39 States Malaysia Australia gt U Norway Russia Indonesia Kuwait Venezuela U nite d Ara h Emirates a d Qatar 39 Unite States Mexico Russia 39 United Arab Emirates Algeria 39 A 1 Nigeria Saudi Wag Arabia Figure l 45 Estimated proven world reserves of crude oil and natural gas January 2006 Note that inclusion ofthe fuel in Canada39s tar sands discussed later in the chapter would increase world oil reserves by more than 39lSO billion barrels and make Canada39s oil reserves second only to those ofSaudli Arabia Source verages ofestimates ofBP Statistical Review Oil and Gas Journal andWorld Oil as summarized in international Energy Annual 2006 as Energy information Administration 0 Impact of Exploration and Development 0 Exploration Range from negligible remote sensing techniques a signi cant such as projects like the TransAlaska pipeline Impact for exploration includes building roads exploratory drilling and building supply lines to remote areas Except in sensitive areas these activities generally cause few adverse affects to the landscape and resources 0 Development Development of oil and gas elds is another story Such processes include Drilling well on land or beneath the sea Disposing of wastewater brought to the surface by petroleum Transporting the oil by tankers pipelines or other methods to re neries Converting the crude oil into useful products At every step there is well documented potential for environmental disruption As a result of energy shortages there is pressure to develop new oil elds in offshore areas and wilderness areas such as the Arctic National Wildlife Refuge ANWR in Alaska where several billion barrels of oil are located 0 Argument for Lecture 22 7 US needs more oil and development in ANWR would reduce the amount of oil we import New oil developments will bring jobs and economic growth in Alaska New techniques for exploration and drilling of oil wells have caused reduced environmental damage than in the past 0 Argument against Even the most favorable technology will adversely affect ANWR Some wilderness areas should remain wilderness and drilling will permanently change ANWR Development of oil elds is inherently damaging as it requires an extensive industrial complex of machines vehicles pipelines and people The oil beneath ANWR will not be a signi cant contribution to the US oil supply Although it would spread out over decades providing a few of our total oil consumption during that time in total the ANWR oil itself would provide a 6 month to 2 yr supply 0 Impact of Oil and Natural Gas Use 0 Oil Mining Mess Development of oil rigs transportation waste disposal and leakage Severe air pollution results from the burning of oil Puts tons of C02 into the atm 0 Natural Gas Mining lssues potential for explosion Puts tons of C02 into the atm Future of Oil 0 Recent estimates of proven oil reserves in the world suggest that at present productions rates oil and natural gas will last a few decades 0 Once we reach peak production there will only be less and less oil available for use and that peak is likely to occur within our lifetime 0 Oil Production amp Consumption Lecture 22 TA B L E 391 1 Statistics of Oil Reserves Oil Production and Oil Consanitationi1 HEEEW H ESi Prodeletion C n imp l a Country isilliion bbll miilions bbiiday millions lbbiitllay Saudia Arabia 265 85 14 liraq 1 15 24 05 Kuwait 99 113 03 lirao 96 38 11 United Arab 63 26 03 Emirates Russia 54 10 25 lli39enezuellia 48 313 China 31 33 49 Libya 30 14 02 M exiczo 27 36 1 N1 igeria 24 22 03 United States 232 81 200 Qatar 15 06 003 Norway 1 0 34 02 Algeria 9 115 02 Brazil 3 136 21 World 1 032 752 quot39Data tomes from various sources The countries listed are the top is in terms of total reserves Waking population into account has 39359 lziloili39parsonr Saudia Arabia has 1085 bbliperson Russia has 335 bbilfperson and the 5 has i l obliperson 339The 5 largest consumers worldwide are 35 20 Japan 31 China is t39a39ermar nir 23 Russia 25 South Korea 21 Note that the ilargest consumers are not countries with large reserves liabvlle i41 Earth Portrait of a Planet Elie There is evidence that we are heading toward a potential crude oil crisis 0 O 0 We are rapidly approaching Peak Oil Production expected to occur between 2020 and 2050 At current rates of consumption one barrel is discovered for every 4 barrels consumed At this rate is expected that crude oil production in the US will be completely exhausted by 2100 0 Bottom Line 0 Between the mining transportation processing and use of fossil fuels we are creating tremendous amounts of air and water pollution as well as ruining vast amounts of wilderness Because fossil fuels are nonrenewable and we are consuming them faster than they can be replaced they are not a sustainable resource Lecture 22 o What do we do 0 Need major educations program that inform people and governments of the pollution and depletion problems associated with fossil fuel use 0 We need to transition from oil and coal to natural gas 0 We need to start looking for alternative energy sources solar wind power hydrogen geothermal and many others Lecture 19 Mineral Resources 0 Resource vs Reserve 0 Resource Concentration of naturally occurring material solid liquid and gas in or on the crust of the Earth in a form that can now or potentially be extracted for pro t 0 Reserve The portion of a resource that is identi ed and is currently available to be legally extracted for pro t 0 What are we trying to extract 0 Metal Opaque shiny smooth solids that can conduct electricity because their atoms are held together by metallic bonds 0 Ore a rock in which a valuable or useful metal is present in suf ciently high concentrations to make it economically worth mining Smelting quotNative Metalsquot are rare Gas escapes Conveyor belt Ore added Reactions go to completion here I Slag extraction Brief history of Metals Copper age 4000 BCE l Bronze age Copper Tin 2800 BC Alloy l Fe age 1300BC 0 Fe Iron 0 Aluminum Ore Pb Ore Lecture 19 0 Cu Ore Precious Metals Nonmetallic Resources 0 Igneous Minerals Quartz feldspars mica o Evaporites Halite gypsum calcite Clay minerals Gravel and sand 0 Metamorphic minerals Talc asbestos garnet graphite diamond o Dimension Stone Granite limestone sandstone marble OO 0 How are the materials made 0 lgneous Deposits Figure 1 5 lEaI39ih Pariraii iii a Hamlet are D 2003 W WNgtorta n 8 Company Inc 0 Sedimentary Deposits Lecture 19 Denser minerals deposited where water ow is slowed lighter minerals carried on Blocks of one fall r I down and i 3 break up i I 39 7 Grains are mined by m er current FIGURE 1514 The process of forming a piaceii deposit Ore I E bearing rock is eroded and clasts containing native metals fan into a stream Sorting by the stream concentrates the metals 1 N Hydrotiiermo fdeposii is al Doi Two 4 39 Film 15 Earlihmamilofl Pillnauu39h cl 20W MW quotman a Company IM 0 Biological Deposits Lecture 19 Copyright 2008 Pearson Prenlice Hall Inc 0 Notice that each of these processes takes hundreds and thousands of years to complete 0 This makes minerals and rocks a NONRENEWABLE RESOURCE How do we extract these materials Mining 0 Underground Mines 0 Surface Mines Open Pit mining Strip Mining 0 Underground Mining 0 Disturbs a relatively small area 0 Tunnels follow the ore body closely minimizes the amount of non ore rock removed 0 When mining is complete shafts are sealed Lecture 19 Outcrop of ore body Stubs surface ore body ait on El Planet 3i D 20 W W Norton 5 Compa my Ilnc Figure 1 521 Ealrth P 0 Surface Mining Open Pit Mining 0 0 Practical when a large 3D ore body is located near the surface Most the material in the pit is valuable ore and extracted for processing Leaves a huge gash in the ground and causes major water pollution problems 0 Surface Mining Strip Mining 0 O O 0 Mostly used to extract coal Works when the material of interest occurs in layers that near and parallel to the surface Overlying soil vegetation and rock are stripped off and the waste rock and soil are dumped back on top Causes major problems with chemical and sediment pollution as runoff is very common as well as mass wasting Reclamation Lecture 19 0 Additional Env Mining Issues Acid Mine Drainage and air pollution Impacts and Remedies 0 Death of plants animals and people caused by mining activity or contact with toxic soil water or air 0 Changes to the ecosystem by altering the nutrient cycle groundwater and surface water availability and quality 0 Environmental regulation addresses problems such as sediment air and water pollution and demands reclamation of land after mining 0 Working on regulating on site and offsite containment and treatment of waste products 0 Biotechnology is beginning to be used 0 Minerals and the Economy Lecture 19 U5 EXPORTS OE MlllNllERAL RAW MATERIAlILS AND PROCESSED MATERIALS OF MINERAL ORIGIN metols chemicols fertilizers etc 36 loillion DOMESTIC MlllNERAL RAW MATERIALS FROM MINING Copper ore iron ore soncl oncl grovel stone eic Volue 3 8 billion MilNlERAL MATERIAES IquotR139IME5 EDI DOMESTICALEY Aluminum brick cement copper lertllizers steel Elli 139 i billion METALS ANlD MINERAL PRODUCTS RECLAIMEID DOMESTICALLY Aluminum gloss steel etc 22 lblllion US HMlPORTS OE PROCESSED MUNERAL MATERIAES Metols chemicols etc 49 billion VALIJE ADDED TO GROSS DOMESTHC PRODU39CT BY MAJOR INIDMSTlRlIIES TllIAT CONIS39IUME PROCESSED MINERAL MATERIAES U squot ECONOMY Gross Domestic Product 7530 billion 5 lIlMPORTS OF MlllNERAL RAW MATERIALS Copper 8 iron ores etc 3 billion Copyright 2008 Pearson Prentice Hall line A Little Economics 0 Major Factors that determine the value of a mining area Value of the mineral or metal extracted Concentration in a particular deposit Source rock containing the material Distribution of Mining Deposits 0 Where are the mining deposits located Ore deposits are formed under very speci c circumstances so it should come as no surprise that the known economic mineral deposits are very unevenly distributed throughout the world Lecture 19 8 Certain countries are rich in many minerals other countries in only or two and some places in none 0 Here in the UShow much do we use 0 15000 kg 15 tons of geologic resources are used per capita each year 0 Keep in mind that the US represents only 5 of the world s population 0 Longterm availability of Mineral Resources 0 15 tons of resources are used per person each year 0 Therefore the population of the US consumes 4 billion metric tons of geologic materials per year 0 To create this supply 18 billion tons of material must be mined each year 14 billion of which will go to waste 0 At the rate we are using them some of these resources may be exhausted in only decades to centuries o The shortage may be temporarily relieved in the future due to If the supply becomes depleted enough and prices rise uneconomical deposits may become worth mining New reserves or new ways of mining become available 0 DON T COUNT ON THESE HAPPENING Not environmentally responsible Only temporary soutionsat some point the cost of mining will exceed the worth of the material 0 What should we do 0 Possible Solutions Find more resources Find a substitute Do without Use less and make more efficient use of what we have Recycle Lecture 4 1 Biodiversity The variation of species within a given ecosystem biome or for the entire Earth 0 Why does it Matter A healthy Earth should be one that 0 Moves nutrients from places they are not needed to places they should be 0 Eliminates waste 0 Has stable temp atm and oceanic comp that does not uctuate wildly o Capable of responding to disturbances in ways that minimize their consequences 0 Biology and Earth have a symbiotic Relationship 0 Biota are instrumental in the regulation of Earth s systems 0 The more regulated the Earth the more diverse the biology o For most communities diversity increases from the poles to the tropics and the highly diverse communities exist within 1020 degree of the equator 0 As such Earth s health can be measured by the of species it supports 0 Looking back 0 What we know about past biodiversity comes from fossil records which may not be an accurate representation since there is a problem with fossil preservation 0 Life has been present on Earth for 35 billion yrs but the initial explosion of life occurred 550 million yrs ago 0 Within 100 million yrs the number of marine organism species reached a rather constant value which has persisted till today 0 Biodiversity has been oscillating since the initial explosion There have been 5 major disruptions to the global biodiversity over the last 500 million years Mass extinctions o All appear to be sudden 0 At least 40 of life previously in existence became extinct 0 Which species lived and which died was completely random 0 The extinction event was followed by a period of recovery as room was made for new organism to replace the functions of those that had gone 0 Two particularly signi cant extinctions were 0 Permian extinction 250 million yrs ag 95 of all species went extinct Lecture 4 2 o CretaceousTertiary 65 million yrs ago 75 of species went extinct Ermine Eras Eras Periods E 7 quot ftn mmmi 7 K E Mesozoic Qw tcmw E Tertiary E m m Palmama a E U E a 7 i t Eretaeeoua 3 u E Jurassic i H E Triassimz nilquot E quotquot quot Permian E PEllfl th i a in ii L Missmsppan 11 E q 39 a 5 Hanan a 2 E a Silurian m i mn 3 ambrim fill r 39 Hill 7 is i What do we learn from this 0 On evolutionary time scales new species continually develop while others go extinct o The average lifetime of a species is between 1 and 10 million yrs 0 Considering life has been present on Earth for 35 billion yrs there has been an unimaginable of species that have evolved and gone extinct over that time period 0 However the fossil record shows that the rate of speciation is slightly greater on average then the rate of extinction A Little Numbers Game Lecture 4 How many species are living today 0 O O 0 Don t know for certain 14 million species have been described and new species are being found faster then they can be catalogued How many species have yet to be discovered Estimates range from 10 million 100 million How many go extinct each year We do not know 0 Because we do not know how many species there are it is likely that many species go extinct without us ever knowing they existed In addition many of the numbers that are reported concerning estimates of habitat destruction and species loss are measured by different techniques in different regions over time Frequently these estimates are made on detailed studies of small regions which are then extrapolated to the larger scale In order to determine the of extinctions per yr we must multiply the of species which we do not know by the extinction rate which we also do not know to arrive at a of extinctions per year that obviously has little quanti able meaning Although there is a large amount of uncertainty in these numbers this is not a problem for our purposes as the estimates of species loss and habitat destruction are sufficiently large that it is obvious a problem exists even if precise numbers are aren t available Is the loss of one species as important as the loss of another 0 Not necessarily 0 Because there is an interdependency among species in an ecosystem if a quotkeystone speciesquot a species that plays a vital role in the operation of an ecosystem goes extinct it may set off a domino affect that results in the extinctions of various other species in the ecosystem As such biodiversity should not be measured simply in terms of the number of species but should also include the number of interactions between them each ranked by the level of importance to the ecosystem The Modern Extinction Lecture 4 4 o Archeological evidence shows the modern mass extinction began when the rst humans evolved and spread to colonize larger and larger areas 0 Present Day 0 As we move forward in time the predominant agent of destruction has changed from overhunting to habitat destruction and the pace of species loss has increased dramatically o It is becoming increasingly dif cult if not impossible to nd landscapes anywhere in the world that have not been modi ed in some way by human actions 0 With few exceptions land use leads to a reduction in biological complexity and reduced biological diversity 0 Humans annually absorb 42 of the Earth s terrestrial net primary productivity 30 of its marine net primary productivity and 50 of its fresh water 0 40 of the planet s land is devoted to human food production up from 7 in 1700 o 50 of the planet s land mass has been transformed for human use 0 Tropical Deforestation o The greatest rate of species loss today is found in tropical forests The climate of these forest regions are characterized by high rainfall in excess of 2 myr high mean annual temps and low seasonal variability 0 These forests cover 6 of the land surface yet they are thought to contain over half of the plant and animal species on Earth 0 In addition unlike temperate forests which will regenerate to something very similar to the original forest after 100 years after clearance a tropical rainforest takes hundreds of years to grow back to its original state In some cases original rain forest may never return 0 Why are the rain forests so sensitive o Temperate Forests Main nutrient reservoir is in the soil The tree s seeds tend to be very resistant to stress and lay dormant for long periods ready to germinate when the right environmental conditions return When a large area of temperate forest is cleared and then abandoned grasses will spread shrubs and a Lecture 4 5 few trees will appear and eventually the spreading vegetation cover will produce the temperature moisture and shade conditions that frequently promotes the return of the original forest species 0 Rainforest Main nutrient reservoir is in the biomass NOT THE SOIL Once forest is cleared heavy rains was away whatever organic material is there leaving the soil extremely acidic and nutrient de cient Seeds of tropical rain forests are less resistant then those of temperate forests and typically germinate within a few weeks Eventually vegetation and forest cover return but the forest composition is normally very different from what was there before the land was cleared There is another major difference between species loss in temperate and tropical forests o Temperate Forests ln temperate forests many of the plant and animal species have wide range distributions around the forest 0 Rainforests Some tropical species are widely distributed but many live only in con ned geographic areas 0 Quite clearly the greatest potential for species loss is in the tropical forests How much loss are we talking about Lecture 4 6 itii ihz il i arnst wa r EEDE Furnnst awsn r 0 Amount Forest Clearance In 1989 there was about 8 million km2 rainforest in the world12 of what existed in prehistoric times and roughly the size of the contiguous 48 US states In the 1980 s this forest was being removed at a rate of 18yr 140000 Km2 per yr an area to the size of Florida The rate of forest clearance in the 1990 s was slightly lower but not statistically signi cant 0 Impact on the biota A conservative estimate from a Harvard University professor concludes that 27000 species are lost each year That equals 74day and 3hr If we use 10 million as a conservative estimate of the total living species the natural extinction rate should be around 10yr That means the current extinction rate is as much as 2700 time faster than what it should be 0 Reasons for Clearance 1 Agriculture 0 Agricultural use 80000 km2yr is burned and cleared to grow crops 0 Practice is called quotslash and burnquot agriculture 2 Logging 0 Logging 50000 km2yr of forest is cleared for timber pulp and other wood products Lecture 4 7 0 Mostly taking place in West Africa and Asia 0 Half of what is cut is exported with largest amount going to Japan and the 2nCI largest going to US 3 Cattle Ranching o Cattle Ranching 20000 km2yr is cleared for cattle ranching 0 Mostly taking place in Latin America 0 Much of the beef used to go to US but now is consumed in Latin America or exported to Europe 0 Cattle Ranching is particularly destructive because once large areas are cleared for pasture soil degradation erosion and compaction from hooves and vehicles soon make the land unusable requiring more forest to be cleared 4 Mining 0 Extinctions Elsewhere 0 The tropical rain forests have the largest extinction rates but they are not the only places where species are at risk 0 Around the world numerous areas have large numbers of endemic species threatened by the loss of habitat 0 Hot spots Areas with many species that exist no where else and that are in the greatest danger of extinction as a result of human activities 0 Why should we care 0 Instrumental Value The degree to which the existence of a species bene ts others 0 Intrinsic value The value for its own sake whether it bene ts others or not 0 Why Should we Care Instrumental Values 0 Medicine 0 Scienti c Value 0 Recreational and Aesthetic Value Lecture 4 o Stabilizes oceanic atmospheric ad soi comp 0 Waste breakdown 0 Agriculture 0 Consequences of losing biodiversity Devastation to the food industry A food crop such as corn or rice in its natural state is likely to consist of many different strains growing together Some are more productive than others some more drought resistant others more resistant to different pests In any year whatever the conditions whatever pests ourish there is good chance that some corn or rice will grow whichever strain is best adapted to those particular conditions Over time the environmental conditions change and the pests and diseases that attack a particular plant evolve At the same time the crop pant also changes and new strains evolve that are resistant to the new conditions Vitality depends on diversity 0 Consequences of losing biodiversity Devastation to the food industry 0 Approach of modern agriculture is uniformity 0 Bottom Line 0 What we have to realize is that we are not separate from the rest of Earths biota and are supported by the rest of the Earth system Without the rest of the system in place we could not survive 0 Our existence depends on the continues presence of a ourishing biota and as we have seen diversity enhance the health and vitality of the biota o The greater the number of species in an ecosystem the healthier the ecosystem will be 0 The more diverse the ecosystem the greater the chance it can survive disruption Lecture 7 Igneous Rocks Rock Aggregate of minerals in which the minerals retain their individual properties 3 Major categories of Rocks 0 Igneous Rocks Rocks that have solidi ed from magmalava o Sedimentary Rocks Rocks formed from the accumulated products of weathering o Metamorphic Rocks Preexisting rocks that have been changed as a result of exposure to heat pressure and chemical uids Rock Cycle Geological processes that turn one rock type into another ogWIOn Sedimenldr rocks at Metamorphic rock Copyright 2008 Pearson Prentice Hall Inc Igneous Rocks Rocks that solidify from magmalava Intrusive vs Extrusive Magma vs Lava o Intrusive aka putonic Solidi es Underground 0 Extrusive aka volcanic Lecture 7 2 Solidi ed Earth s surface 0 What kind of rocks does madmaIava produce 0 Two conditions that affect the type of rock crystallized 1 Composition 0 What is the composition of molten rock 0 Main ingredients Si and O o Other primary elements Al Na K Ca Fe and Mg 0 Volatiles C02 N2 H2 502 0 When molten rock cools down it goes through a process called crystallization in which freely moving atoms lock into speci c locations in a crystal lattice 0 Do all the minerals in the rock crystallize at once NO Each mineral has a different crystallization temperature 0 The minerals crystallize by means of a process called quotfractional crystallizationquot which is dictated by Bowen s Reaction Series Tern erature Igneous Regimes Bowen 3 Reaction Series J Rock Types l 4 7 7 nm mr a v Ultramafic peridotite AndeSitiC andesi tediorite Low temperature last to crystallize Fractional Crystallization Minerals with higher melting points crystallize before those with lower melting points Results in a separation by density 0 Composition of molten rock constantly changing Lecture 7 3 2 Rate of cooling Affects the texture texture depends on the rate of cooling 0 The overall appearance of the rock based upon the size and arrangement of its minerals texture o The longer the magma takes to cool the more time the atoms have to get together larger xstals o If it drops too quickly atoms freeze where they are instead of adding to existing crystals which results in either many tiny crystals or in some cases no crystals at all 0 Texture Phaneritic Coarse Grained top picture Slow cooling 0 Texture 090quot aphanitic Fine Grained bottom pic quot Fast cooling 0 Texture Porphyritic Coarse Fine Grains I Slow cooling followed by fast cooling aphanitic matrix phenochsfs Use your browser39s quotbackquot bu nn to return 0 the data page 0 Composition Texture Rock name 0 Composition What depth the magma came from Magma Temperature 0 Texture Speed of cooling Where the rock cooed Glassy texture o Obsidian Rhyolitic magma so thick and pasty that sizeable crystals cannot form before the cooling of the magma freezes crystal development 0 Volcanic Glass The glassy rind that forms on pillow basalts during underwater eruptions right o Pyroclastics Materials that erupt from volcanoes when exploding gas bubbled disrupt the magma into bobs Lecture 7 o Pyroclastic Classi cation TABLE 41l Classification of Pyroclastic Materials Size of Fragments mm 0 2 64 gt Name oil lloose fragments ash lapilli bombquot Name olc rock composed of many fragments tuff lapillistone agglomerate lapilli tuff Lapilli arid bombs of mafiCintermediate composition are called scoria whereas those of felsic com position are pumice Compositional terms can be used as modifiers eg basaltic bomb rhyolitic tuff quotAGlassy Glassy anol vesicularquotquot quotquotFragmental How do we name an Igneous Rock Composition Texture ii 3 We wg g mqma39gaw we AA ii I my i w w 0 Economic Angle Pegmatite Exceptionally Coarse Grained 0 As magma crystallizes gets richer in H20 0 Pegmatite melt is the last to crystallize o Atoms can move around very rapidly because of high water content allows them to grow very large very quickly Lecture 7 Lecture 3 1 Minerals The Building Blocks of Earth Minerals What are they 0 Must be naturally occurring 0 Must be inorganic 0 Must be a solid 0 Must have internally ordered structure atoms be arranged in a de nite patterncrystalline materials 0 Must have a de nite chemical composition slight variability permitted What are minerals made of and how are they produced 0 Like all matter minerals are made of individual elements 112 total but 22 of them are manmade and only exist in lab 0 What are individual elements made of l Atoms o What are atoms made of Nucleus electrons The Nucleus o Protons charged 1 unit weight 0 Neutrons no charge 1 unit weight 0 Atomic of protons in the atom de nes the name of the element 0 Mass sum of the elements protons and neutrons o Isotope 2 elements with the same of protons and a different of neutrons Electrons o H charged 0 virtually no mass 0 moving at the speed of ight so that it often is described as electron cloud The Atom 0 Neutral Atom The of electrons must equal that of protons 0 Ion Charged Atom Electrons have been gained or lost and do not the of protons Lecture 3 2 Electron shells J Proton otomic weight ll id 0 Neutron atomic weight ll 0 Electron atomic weight 0 Copyright 2008 Pearson Pre Electron Con guration of Atom 0 Electrons occupy different energy levels or shells surrounding the nucleus 0 Each e is located at a certain distance from the nucleus This distance is associated with the energy level of the e 0 Each energy level can only hold a xed number of electrons The electron con guration reaches the most stable state when the number of electrons in the outmost energy level is maximized o Valence electrons electrons in the atoms outermost shell 0 When atoms react they try to organize things such that their outer shell is completely full mimicking noble gas con guration 0 As such the of valence electrons plays a major role in determining the behavior of an element and therefore what other elements it is grouped with in the periodic table 0 Why are atoms connected with each other 0 To reach the most stable state satisfy the maximum shellelectron con guration individual atoms may give out to acquire from share electrons with other atom of the same or different elements to form chemical bonds 0 Materials connected by chemical bonds are called compounds Lecture 3 3 Elamantal 53ml Elamantfham 39 lrr Eamon 13m 1 Atomil waiehl o How are atoms connected to each other 0 Ionic bond eectrons is are given by one atom and received by another atom Once this givingreceiving process is nished the two atoms are no longer two entities rather they are one compound 0 Covalent bond two atoms share eectrons bonding between nonmetals and nonmetals Bonding between nonmetals and nonmetals t m g 1 gramme or T rl vl EFEH Eli 1E LlEIE TFlEJ NEE ELEETFEN positive negative i l l l icin 0 Metallic bond an atom achieves a more stable con guration by sharing the electrons in its outer shell with many other atoms 0 Metallic bonds prevail in elements in which the valence electrons are not tightly bound with the nucleus namely metals thus the name metallic bonding ln metallic bonding metal ions are tightly packed so their outer shell electrons overlap so each electron Lecture 3 becomes detached from its parent atom delocalized In this type of bond each atom in a metal crystal contributes all the electrons in its valence shell to all other atoms in the crystal 0 van der Waals force quot Forcequot not a quot bondquot Occurs when electrons are not equally distributed on all sides Creates a weak negative charge one side and a weak positive charge on the other Attracts other weakly charged particles due Shanna charm I paranoia i Flualmtm quot 7 mpgquot A swamId 1 mol aeullw Emmag mpnmtmn g 39 illuurzu Iirm impinging i it i i Elam air Waals intemalmn o The Structure of Minerals 0 Gas vs liquid vs solid 0 Gas free atoms in space 0 Liquid free atoms within materials giving the material de nite volume but no de nite shape 0 Solid restricted atoms within materials given the material de nite volume and shape Solids Glass If the atoms are randomly piled up in a material then the material is said to be glassy Crystalline If the atoms are orderly packed in a material then the material is said to be crystalline 0 Minerals are crystalline o If allowed to grow freely it exhibits unique external shape that re ects its orderly internal atomic arrangement 0 Physical Properties of Minerals 0 Atomic Structure Composition 0 Properties due to Atomic Structure 0 Mineral Cleavage Lecture 3 5 Tendency of minerals to break along speci c directions or planes that have weaker chemical bonding 0 Mineral Hardness Example Graphite vs Diamond Same Composition different Structure 0 Properties due to Composition 0 Mineral Color 0 When trace elements replace a few atoms of more abundant elements in the crystal there is little affect on physical properties with the exception of COLOR 0 Mineral Streak 0 The color of the residue remaining from scratching a mineral on a piece of unglazed porcelain Different specimens of the same mineral may vary in color but will always have very similar streak o Rxn HCl and C03 0 Magnetism 0 Properties of Minerals TABLE 21 Physical Properties of Minerals Description of Property Factors That Determine the Property Luster describes how mineral surfaces reflect light Luster depends on the smoothness of the mineral surface at the atomic scale which in turn depends on how mobile electrons are within the crystal ens y is the measure of the mass of a substance contained within a particular Density depends on the types of atoms and how the atoms are arranged in the volume of the substance crystal structure The heavier the atoms are and the more tightly packed they are the higher the density of the mineral crystal faces are flat smooth surfaces on minerai exteriors with regular geomet Crystal faces reflect the atomic arrangement of atoms within the crystal struc ric forms ture and produce exterior geometric shapes during growth unless the crystal grows against another crystal Hardness is the resistance to scratching on a smooth surface Hardness reflects the atomic bond strength of a minerai which depends on bond type and the spacing of atoms within the crystal Cleavage describes planes along which a mineral breaks and the shape of the Cleavage forms along regularly spaced internal planes where bonds are weakest resulting fragments in minerals Color results from the interaction of light with the mineral Atomic arrangement and composition deterrnine how light passes through or interacts with the atoms in the crystal39 determining the color Streak is the color of the residue rernaining from scratching a mineral on a The finegrained nature of the powdered residue results in a more reliable nonglazed porcelain plate observed color than the whole crystal 2010 Pearson Education inc 0 There are over 4000 minerals already known 0 50 100 new mineral identi ed each year Classi ed based on their chemical composition 0 The Mineral Classes 0 Silicates 0 Chemical formula ends in some form of SiO4 Lecture 3 6 o Compose the bulk of Earth s crust and all of the mantle quotrock forming mineralsquot Building block of Silicates l SiO tetrahedron 0 Can form an abundance of crystal structures and therefore create very different minerals 0 Some Common Silicates MinerallFormula Cleavage Silica le Slructure Example 0 Olivi nnnn o u 39llainltas al39J aquot P HM 539 Warn 39 m ib f Amplhiljole gr ojup quotlHWW 39l39 ezMsile Sla de Twotiplanas at 032 Qiz iQHllzr act and 1239er 39 Biotite lltilv1gFngAlSiQO nlOHlu2 Min O 399 Muscovite KAlleSlaomllOle Potassium feldspar Orthoclase KAISiJOB Two planes at 90C Feldspars Plagioclase feldspar CaNal l 3i30a Copyright 2008 Pearson Prentice Hall lhc NonSilicates Oxides Chemical formula ends in O Ex hematite Fe203 or magnetite Fe3O4 Sul des Chemical formula ends in S Ex Pyrite FeS Carbonates Chemical formula ends in CO3 Ex Calcite CaCO3 Phosphates Chemical formula includes in P04 Ex Apatite Ca5PO43F Cl OH Sulfates Chemical formula ends in 04 Ex Gypsum CaSO42H20 Halides Binary compound of which 1 part is a halogen atom F Cl Br and At Ex Halite NaCl 0 Native Elements Lecture 3 Gold Au Silver Ag Graphite C 0 Supply you with The nutrients to sustain your bodies Materials you use every day Lecture 8 Mass Wasting the term used to describe any type of downslope movement of earth materials aka landslides Not caused by humans but can be prevented Who s at Risk 0 People living near mountains Slope Types 0 Free Face Talus sope Arid environment with hard rock rocks prone to breakage steep cliffs r if Q I a Free icicle gquot clliitl e l l l R l X l i x a x Talus sloipe 39 x i x e rockfdll deposits f 7 z x r 39 Jr 5 x h 5 l Very horcl strong granite Copy ghl 2008 Pearson Prentice Hall Inc Concave Convex slope made from water softer rock vegetation i Convex slope Relatively week rock Copyright 2008 Pearson Prentice Hall Ino Type of Mass Wasting Lecture 8 0 SI Id es Actual rock slides vs slump T ElLE E 1 Cemmen Types ef Landslides and Either Dewnslepe Meyements Mechanism Type of Fillass Meyement Characteristics FaIIl Heck Fail Individual recite tall threugh the air and may accumulate as talusquot Slurnp Eehesiye EIOCHS cf seft earth material slide en a cursed surface else called a retatlenal landslide Slide Sail Slip Sell and ether weathered earth materiel sllide en a tilted surface at hedr eclt er cahesiye sediment alse called a debris stide er earth slide Fleck slide Large blacks ef hed r eclt slide en a planar surface such as layering in sedimentary er metamerphic reclrs yaianche Granular filew at variants cerehinatiens at sneer icer ergan ic debris lease reeks ar sail which reeves trery rapidly dawnslepe Fm lBreed irery slew dawnslepe meyelnent ef racks and sail 39 W Earth flew Wet partially adhesive and internally delermed mass at sell and weathered recilt Debris flew Fluid mixture cf reclts sand mud and water that is intermediate between a landslide and a water fleed inclddes mudf lews and Iahars Samples it carnhinatien at tyre er mere types at sliding fluewage and eccasienally Falls terms where ene type at landslide than gas late an other as it mates dewrtsleae Slides Hrla aege Copyright 2008 Pearson Prentice Hall Inc Found in arid environments and shale Hazards soil slips Slides Blocks of bedrock or well consolidated material move parallel to a slope Zones of weakness fractures bedding planes weak clay layers foliation plane 0 Sumpmg Why get Slumping Slumps Curved slip surfaces Common in unconsolidated earth material and in other weak rock types like shale Found in humid environments Lecture 8 Sandstone 79 9 p j3939 1 Slip plane Rotated a Rock slump Soil slump Copyright 2008 Pearson Prentice Hall Inc Copyright 2003 Pearson Prentice Hall inc Creep imperceptibly slow movement of regolith Soli uction Very slow downslope movement of saturated soil and regolith larger scale of creep Earth Flow Partially saturated debris and sediment High viscosity Debris Flow Highly saturated debris and sediment High viscosity Mud Flow Highly saturated ne grained sediment Extremely Fluid consistency similar to cement Rock Avalanche Large mass of snow ice and rock debris that slides ows or falls rapidly down a mountain happens in dry environment Debris Avalanche moving masses of rock soil and snow that occur when the ank of a volcano collapses and slides downslope happens in dry e nvi ro n me nt 0 C re e p Movement Thick Ground suriiace during freezing rego th Regali th E Movement Fragmentilng L during thawing bedrock Winter sllope v Summer Marker bedl J quot sllope i F MI 192 unluFo allu ath no 2am Wu39WJNononl Company inc El 2003 WWNumu I Gumpmglluc Lecture 8 4 Factors Contributing to Creep Frost Heaving Freezing and thawing without necessarily saturating the regolith causing lifting and subsidence of particles Wetting and Drying Causes expansion and contraction of clay Minerals Growth and Decay of Plants Causes wedging moving particles downslope cavities formed when roots decay are lled from upslope Activities of Animals Worms insects and other burrowing animals displace particles as do animals trampling the surface Dissolution Mineral matter taken into solution creates voids in bedrock that tend to be lled from upslope Activities of snow Seasonal snow cover tends to creep downslope and drag with it particles from the underlying ground surface 0 Flows Why get ows Lecture 8 5 Main ingredients water steep slope uncompacted sediment A non permeable layer will allow the buildup of water and trigger ows 0 Falls Why get falls Joints andor fractures perpendicular to the bedding plane near the ocean on the coast Complex Movement 0 Multiple different types of mass wasting involved with 1 landste Lecture 8 RE 1 6 1 2 Each type of mass movement has a range of velocities dependingon the steepness slope and the water content of the mass In general steeper slopes make for faster movements of mass movements also differ in the degree to which they remain coherent here coherent Soli ucriom Creep Rock glacier Debris slide Mud ow Snow avalanche Debris avalanche 39 Typical velocity of mass movement 39 I fast 0 Variables in classifying down slope movement 0 O O 0 Type of movement Slope material hard rock or unconsolidated rock Amount of water present drainage needed or avalanche prone Rate of movement creep problem or barriers needed now Subsidence O O 0 Flat ground failure Sink holes Form of collapse of sediment What Causes Landslides O 0 Stability of a slope is determined by the relationship between driving forces and resisting forces Driving force gravity weight of the material Resisting force friction and cohesion molecules trying to create a temporary bond with other nearby unpaired molecules Slope stability is determined by computing quotsafety factorquot ratio of resisting forces to the driving forces If SF gt 1 stable If SFlt1 expect slope failure X Resistance force FR Resistance force FR Fd gt FR Fd lt FR Downslope Normal force Fd force Fn Steep slope 7 39 Gentle slope Pull gravity a Figure lE13 Earth Portrait ofa Planet 3Ie 2008 W W Norton 8 Company Inc M Lecture 8 7 0 Factors that Determine Slope Stability 0 As local conditions change the slope conditions change increasing or decreasing the SF 0 Driving and resisting forces are determined by the inter relationships of the following variables Slope Angle Climate Vegetation Water Time what may seem safe and stable today may not be safe and stable in the future 4 Safety Factors 1 Slope Angle o The steeper the slope the stronger the driving forces and the more frequent and intense the mass wasting o Creep gentle slope falls and avalanches soil slips very steep slopes 0 Angle of repose steepest slope that a pile of unconsolidated sediment can have and remain stable 0 Finer grains have a smaller angle of repose then coarser grains Particle size makes a difference 0 Angular grains are more stable than round grains angular grains can lock into each other and create more friction o Poorlysorted sediment is more stable than wellsorted sediment smaller grains can ll in the holes between the larger grains 0 a Fine sand b Coarse sand Angular pebbles Figure ll i 4 Earth Portrait of a Planet Elle 2008 WW Norton 8 Company limit 2 Climate o Subhumid and humid regions Complex landslides earth ows and soil creep are common 0 Arid and Semi Arid Regions Rock falls debris ows and shallow soil slips are common Lecture 8 Wet climate rapid weathering dense vegetation Vegetated regolithoovered hillsidles Great Smoky Mountains National Park Tennessee Thick regolith 39 Bare sandstone Dry climate slow weathering tnih regollltn eroded away sparse vegetation Slump creep lFlegolith tin to absent 4 Dry sandy stlrealmbed Hook fall Gullies eroded in weathered shalle Bare rockyr hillsides Arches National Park Ultah 2010 Pearson Education Inc 3 Vegetation O O 4 Role of Water O 0000 Provides a protective cover that cushions the impact of falling rain This cushion allows the water to in ltrate into the slope while retarding surface erosion Plant roots and strength and cohesion to the slope materials and increase the resistance of the slope to landsliding Add weight to the slope you have to be careful with what kind of vegetation you use Double edged sword Water helps bond together molecu Too little or too much can be harm39 Too much creepmud ow Too little avalanches Double edged sword r V Water partlytins a s dding a Small amount of water 1 produces thin tilms oi water along some t I grainl contacts which increases the cohesion and the angle of repose This r is why you can hoitd steepwalled 39 sand castles from moist send but not dry sand quot quot 39Wster separates sand grains Adding a large amount oi water forces the grains apart so that water completelyr surrounds and separates grains Grains are no longer in contact whioh decreases llriction and causes the sand to flow litargla amount of water quot decreases l niotion l 2MB Pearson Education lino Lecture 8 9 How Quicksand J informs 1 Sand Particles Underground Water Source potential slumping umpmg occurs 3913 1 house With 1 r ocean 1mistiii unstable ocean cliff stable ocean cliff erosion of base I of slope 0 External Triggers of Mass Wasting changing the slope strength 0 Shocks or vibrations Earthquakes Trucks and construction sites Both moving molecules around and making the foundation distribution different Adding Water when you build a new city with lots of roads the water in the ground all has to go to a different place Removing Strong Vegetation 0 Major Anthropogenic contributions to the problem 0 Timber Harvesting and road building 0 Urbanization Adjust slope angle Remove vegetation Add water and weight 0 Vaiont Dam October 9 1963 o What happened 0 250 million m3 of rock and other debris moved at speeds of 59mieshr down the North face of Mt Toc and landed directly into the dammed reservoir 0 Slide material completely lled the reservoir for 11 miles along the axis of the valley to heights of nearly 500 ft above the reservoir level 0 Earthquakes and waves more than 295 ft high were produced ooding the entire down stream area and damaging the upstream area with propelled rocks and water Lecture 8 10 0 Within 7 minutes the entire episode slide and ood was over 0 2500 dead countless homes and buildings destroyed 0 Why did this occur 0 Mountain was composed of fractured limestone shale and weak clay layers that were inclined toward the reservoir 0 Area was very steep which created a strong driving force 0 Water pressure and saturation was increased in the valley rocks because of water in the reservoir 0 Increased rains a few days before the landslide added extra weight to the slope Minimizing the Landslide Hazard o Requires identifying areas in which mass wasting is likely to occur Design engineering structures to prevent landslides Warning people in danger areas of impending landslides Controlling landslides after they have started moving Identi cation of potential landslides left 0 Generate Hazard Maps right Swampy water has drained llow areal out of cracked ground OOOO Cracked walls and roof sinking foundation Head Overtight power lines Tiilted utility poles Hammock ridges Mos Flul o 9 El loo cre r genrle slopes subiecr col shallow slidling soil p and selllemenl Ii Genlle lo modieralely sleep slopes in older stabilized landslide debris 39 Z Inaclive on Id 5 I e I geologically old a a subiecl lo aelllemenl sail creep and Y Yes Y Yes i ll w cl deep land Id 9 fence The land use would normalll b 39 39 r i y e expected J Sleep to very steep slopes sublecl lo Regallth lo be permilled provided lhe geologic mosswasting by soil creep slumping Yes Yes Yesquot dale and or engineering solulions are and rock lull surface Bedrock Cracked and lavorable However ll iere will beinstarices Genne no very leap I PBS i I b satandary slump displaced where the use will no be approprlole mo39erial subied 0 SI ding l P g Noe N N highway 0 and soil creep quot N Thl39d Id ll b ldll l Igur21612 lEartth Drtrait D fa Planet are e on use WOU norma elem D MOVani Shallow llt3ml landslide N0 NC ND not be permilledt However e ircumslonces where geologic dold leasl and or engineering solutions will permit gable h user 0 2003 W W Norton E Curnpaniy Inc deep landslide subiecl lo No NO NO UI39E l l Irma lb 0 Prevention of Landslides 0 Do NOT Load the top of slopes Cut into sensitive slopes Place ll material on the slopes Drainage control Grading Slope supports Drainage Controls 0 Surface drains water is allowed to funnel down slope Lecture 8 11 0 Soil cement applied natural type of glue to plug in pores so water doesn t saturate and weigh down slope Slope Supports 0 Large walls to support the weight with drainage holes at the bottom to let water run out Drain lo lei woiler 7 from slope out Polen rloill sllip plane of landslide Piles in slolble rock Concrete reloining wall Copyright 3 Parson Prentice Halli Inc 0 G ra ol n g o C ut a n ol Fi l l Removed b o Terracing Lecture 8 Added lower water table to U nslable J slope Jld channel gt x Terrace slcps 1 remove loatlL catch debris Riptap ahaor hs WEI energy Filled channel dl H nel away from cliff tel Avalanche to him 39 l1 FIG Ll RE 15 2 3 A variety of remedial steps can stabilize unstable ground a lievegetation removes water and tree roots bind regolith h Redistributiog the mass on a slope eases the load where necessary adds Support whete necessaryr and decreases slope angles cl Lowering the level of groundwater the water table may allow a failure surface to dry out 31 Terracing a steep slope may decrease the load and provide benches to catch dehris e Relocating a river channel stops undercotting and lling the old channel adds support if llipra39p absorhs wave energy along the coasts g A retaining wall traps falling rock h Bolting rock to a steep cliff face holds loose blocks in place it An avalanche shed diverts avalanche debris over a roadway Warning of impending landslide 12 Lecture 8 13 0 Provide time to evacuate and to stop trains and reroute traf c 0 Warning can come from Surveillance Electrical systems Tilt meters Geophones Monitoring of shallow wells 0 Preventing Landslides expensive but well worth the effort 0 O O For every 1 spent on landslide prevention the savings will be from 10 2000 Ex Preventative measures of unstable slope in Utah 300 500 thousand Damage 200 million 0 BOTI39OM LINE 0 O 0 There are a number of both natural and anthropogenic causes of landslides Most people consider this hazard minimal unless they have had experience with it Advice Have a geologist inspect any property you are contemplating purchasing prior to sealing the deal 2 F 4v 3 x FE dkmm um Qimmosm m zzi ctif7IQZKQ A af lggggm i wmgw w e quot3quot L 39 m khwi c39 J if r M e Jro 1 0W6 32 m I itquot w W 2251 slvaunc 1 apmnmmugu e Q m 8 5 Cu v vu ugr 39 u 39 39 39 bl hulakc 94 C GrizM 53955 I qr Var ewrlCIPqf ag T LLQK QIM b mimic 1g 39 c o11 quot v gm my 5 QCLQ n n L I i I I O 0 j Mae3 39 Maiden LHQHSI r39 quot QSNCQ QA d 39U 691 94 clubS ZQLUPntW l r 5 nl h Q mg ljLMLLLJZQWM w c wm ngmmcrg LSJWVW W a fwu VP kraHrv c Crass k gif ggg 50514 P C V w anmvmyuw OW 39 txlf fFD VVWLM quot 39IVIV Vquot39Il i3 gt J39 f x v 1 i f 393 3 3 5L 3vraixx39aj Pacjm I 39 5 WM vh a Ec 39tf Ct 551x050 2Q bf 39 r133 r 39 s 3 ugyw TL 5Z6 r ng xe g Qh i Capabdc MW 3 L39dka Jwacee m gm 7 A nd P 42mm t39 an ffSISl T7Q 1C Id C3 7 I f aacgagg migjbw 5 quot r r 39 gt WWW wry dA rr 4 r H gi g b mjwe i cj 39 NJ 9 39 I 539 39L Cquot39Ce WizangadlrAmt 24451 115 r a Ia 9a miquotng jari Eq a ci mk l 1 I k 6 M w riffam I quot I 39 K 393 f QCng LL eemampp mww ram t 39 x51 qp 1395 7gugg wm t L 39 W 1quot 39 I 3 5 W93 3 W Ix LE bifi cwifl MILIW 393 Wldwf f 3 GmLLLLQQ mounLWEQ i ng 364 hcmvg ek a Alaw MJ quot I I L Q 55ngf esw iwbamgs 4ru ej iw yf L w I quot r u a n v urv v v 39 u I I I I I Upr ftc a 1393 f iuifj f Jrb 39I F HM 1 aquot 39 r aquot 5 quot x Mm 4 qu F m w 1 im2 lezg igm ciiMeiampL i H1A A w m r a 3amp1 gigg izm quot quotquot39 39 39 quotl i 5 1 w 6 0km V3 7 quot 39 I W r 39h rsg a a 4 A if quot m WgTrmULt o cxgg5 i f I q cak 3 I 9 quotrqvi gtikqtfi t Tf im quotq d M Hm 3 b rs7m4 EJmtgaw v H g mm quot 1 A r quot f 11 as s r354 A 7 0 4 l T I f I I I 4 I I r I v um 39 39 39 I I 4 quot 39 f U39III 1 j quot HH a VL 39LLEIJLLQE LLB f Lecture 5 1 Sedimentary Rocks Rocks made from the accumulated products of weathering How do Sedimentary Rocks form 0 Weathering causes preexisting rock to be broken down into transportable pieces called Sediment o This sediment is transported by wind or water and depos ed 0 When nally settled they undergo processes in which the sediment becomes solidi ed to form a sedimentary rock 0 What is weathering o The processes that break up and corrode solid rock eventually transforming it into sediment 2 Kinds 1 Detrital Physmechanical Weathering 2 Chemical Weathering 0 Physical Weathering Physical wear and tear on the rock 0 Chemical Weathering Rocks are broken down on an atomic level 0 Dissolution Water strips out anions and cations from a rock transports them then deposits them 0 Hydrolysis Water chemically reacts with minerals and breaks them down Works faster if the water is slightly acidic o Oxidation Reaction in which an element loses electrons Commonly this reaction takes place when elements combine with oxygen 0 Types of Sedimentary Rock 0 DetritalClastic Sedimentary Rock Formed from physical weathering transportation particles deposition lithi cation Classify by texture packing of individual grains Lecture 5 Particle size mm Rock name Sediment 39 gt2 Conglomerate Gravel 2 1 16 Sandisto ne Sandi 116 12 56 Sil tstone Silt 1256 MudShale MIUIdi 0 Chemical Sedimentary Rock Formed from chemical weathering transportation atoms deposition precipitation 0 Biochemical Sedimentary Rock Rocks that are precipitated through biological processes then lithi ed 0 Organic Sedimentary Rock Made exclusively from biological material Classifying Sedimentary Rocks Lecture 5 Detrital Sedimentary Rocks Texture 7 Composition Rock Name Rounded quartz or Conglomerate 7 7 Coarse chert grains 7 7 Grains over H Angular quartz or Breccia chert grains Quartz Quartz Sandstone Medium 7 r Grains between l l 6 Kispar Ark os e sandsm ne Types of sandstone and 2mm Rock fragments 7 7 7 Lithic Sandstone Fine Grained Quartz and mud 7 Siltstone Very Fine Quartz and mud Shale fissile Types of mudstone ifquot Mudstone No fissility Chemical Sedimentary Rocks Composition Texture Rock Name Visible shell fragments Coquina looselrssmeated a a an Calcite CaCOg 7 Skeletal material will effervesce from cemented with calcite lFossiliferous limestone Biochemical Rocks HCl cement Powder sized calcite Chalk grains 7 7 Calcitic Mud Micrite it Altered plant fragments Very hrit tle Bituminous Coal Organic 7 Fine coarse Crystalline Limestone crystalline V Calcite CaCO Spherical sand grains coated in calcite Oolitic Limestone cemented together l V Quartze SiO 7 Very Fine crystalline Chart if light colored V not or dark colored Chemical Halite NaCl Fine coarse 7 Rock salt l 3Teclll3 liams 7 crystalline 7 Gypsum H W Fine coarse 3 Rock gypsum CaSO42H20 7 crystalline 7 i r 7 Fe hearing minerals Covered in rust 7 iron Stone A Clay minerals Powdery hrittle i ClayStone o What are the most abundant minerals in sed rocks and why 0 All sedimentary rocks are initially the result from weathering of the continental crust Seeing Na K Ca amp Si rich minerals Much less Fe and Mg minerals Detrital rocks Quartz feldspar and mica Chemical sedimentary rocks Clay Evaporites Calcite limestone OOOO Lecture 5 Quartz Chert and int Halite rock salt Gypsum alabaster 0 Where are they formed Everywhere G Iaciai environment Stream environment La ice Beach Sand dunee Aliuviai fan g Deep marine envimnment GI Brooksi GDlier Cengage Learning Lecture 13 1 Rivers and Flooding 0 Historical Perspective 0 Floodplain is the at surface adjacent to the river channel that is produced by the process of regular ooding Flooding is a natural process Floodplain is one of the most naturally fertile soil in the environment 0 As the pioneers moved out west they had a very structured plan for modifying the land Clear the land by cutting and burning the trees Modify the natural drainage 0 From this history came 2 parallel trends An accelerating program of ood control An even greater growth of ood damage 7 Floodplain lGl Copyriihl 2008 Pearson Prentice Hall Inc 0 Streams Rivers amp Drainage Basins o Hydrologic Cycle Cloud Formation Precipitation Copyright 2008 Pearson Prentice Hall Inc 0 Drainage Basins Lecture 13 ID39Eai IaIE divide a railraga basin of stream IE Drainage has of stream A Iiiin was BRIE Hamill illPia lman 351i 9 in ll Hanan I39Eli39 l l39l t Int 0 River Anatomy E lt v Longitudinal Plane of Limit of 1 profile longitudinal drainage basin 2 nu f39l pm I e Tributary Headwaters Distance from mouth Tributary uth Crosssectional profile Figure 11713 Earth Portrait ofa Planet Ble 2008 WW Norton 8 Companylnc Cross Sectional Area of a River Lecture 13 0 Discharge volume of water in a channel passing a point in a period of 1 second ft3s or m3s 0 Used to describe the amount of water a stream carries WxDxVQ Channel Area 0t rectangle Depth 1 lt w The crosssection area of the channel is about equal to the width multiplied by the depth of the flow in the channeL Crosssection area x Velocity Discharge Channel width x Channel depth gtlt Velocity 2 Discharge Units Meters gtlt Meters gtlt Meterssecond 2 Cubic meterssecond 2010 Pearson Educationi Inc 0 Rivers and Sediment Transport 0 Used to transport excess water so we don t ood 0 Used to transport mass wasting from high ground to the con nent Cross Sectional Area and Sediment 0 Total Load total amount of sediment carried in a river Bed Load Suspended Load Dissolved Load Normal Dissolved bed load Rolling ions Suspended load clay Moves during Substrate ood Clast collides and bounces another into water Figure 39Il 7t1d Eartlh Portrait of a Planet Me 2008 W W Norton 8 Companylnc Lecture 13 4 0 Velocity and Sediment Sorting 0 Higher elevation faster waters more energy carries larger particles 0 Lower elevation slower waters less energy Drops larger particles Source 1 ahg g iu w Shallowergradient quot r E gg39 quot 39 itquotTinf r trgieuaf 77 7 7 7 339292 573755 13 3 39 H V 7 quot ex 47 azw i neg Sediment becomes finer throeng breaksp Eek I quot39L x93 Ud g tra ibgbrt When tow stops 3 remainieg materiel stopped Figure 6 4 Typical longitudinal pro le of a stream in a temperate climate Note that the gradient decreases from source 10 1112111211 V r o n p n e l 7 Particle sizes may decrease with breakup downstream Total dlscharge capac1ty and veloc1ty may all Increase downstream esp1 e l decrease in gradient 0 Deltas amp Alluvial Fans o If a river has a particularly substantial load as it reaches the mouth the change in velocity as a river moves into a wide open still medium like plains or oceanslakes often results in a triangular deposition of sediment due to the decreasing velocity of the river as it spreads out over a larger area Sediment Discharge o Streams and rivers generally maintain a quotdynamic equilibriumquot or steady state between the sediment transported by the stream and the sediment delivered to the stream 0 The stream tends to have a slope amp crosssectional shape that provide the ow necessary to move the sediment load 0 Anything that results in a change in the channel s slope or crosssectional area such as increase or decrease in the amount of water or sediment received by a stream effectively changes the velocity of the water 0 This may in turn increase or decrease the amount of sediment carried in the system 0 Therefore any kind of land use changes that affect the shape of the channel andor the streams volume of sediment or water may set into motion a series of events that results in a new quotdynamic equilibriumquot Lecture 13 5 0 Channel Pattern amp Floodplain formation 0 Channel pattern con guration of a river channel as seen from an aerial view 0 Streams do not ordinarily ow in straight lines for very long but usually develop into one or both of the following channel patterns Braided Stream 0 Result of glacier melt water that is coming from mountainous regions to atlands Meading Stream 0 Water speeds up slows down in certain areas Constantly moving and uctuating Lecture 13 Jake Figure 11 722 Earth Portrait of at Planet 3h 2008 WW Norton 8 Company inc 0 The Floodplain and Flooding Yazoo stream Oxbow lake Floodplain1 Floodplain deposits Ancient floodplain Ancient channel deposits and point bar Stream bed gravel Figure 39Ii722d Earth Portrait ofa Planet Sle 2008 WW Norton amp Companyinc o The amount of space in a river channel is suf cient to accommodate the average maximum discharge reached each year 0 In times of higher discharge the stream may over ow its banks or ood Lecture 13 3 i 1 River volley 3 i u 2 o e a 5 3 Q River chonnel m 2 Distance across volley r cl Cross section dcross river volley neor heodwoler 4m Droindge basin boundary 4 Floodplain gt Coosth plain a a C 3 7 739 7 39 m Ocean B 0 Miles E 45 39 I E o River channel 0 100 Kilometers LU 3 Dislonce ocross volley F 0 Map plan view cl Cross secllon across river volley neor hose level Profile of Fox R from A lo B Elevolion above sea levell Distance downstredml lb Longitudinal profile Copyright 2008 Pearson Prentice Hall Inc 0 Factors that in uence NATURAL ooding 1 Total amount and distribution of precipitation in the drainage basin 2 The rate at which precipitation in ltrates rock or soil 3 Topography 4 Some oods result from rapid melting of ice and snow in the Spring 5 Vegetation may reduce ood hazards in several ways 0 Flash Floods amp Downstream Floods o Upstream oods Floods that affect only small localized areas Most often caused by sudden locally intense storms and by events like dam failure quotFlash oodquot a is often the term given to these events 0 Downstream oods Floods that affect large stream systems and large drainage basins Lecture 13 8 Often the result of prolonged heavy rains over a broad area or from an extensive regional snow melt Usually last longer then upstream oods as the entire system is choked with water Downstream Hood Copyright 2008 Pearson Prentice Hall Inc 0 Following a Downstream Flood 0 Characterized by a migrating ood crest o The further downstream the longer a place takes to reach its ood peak 0 More water is added to the ood and it begins to choke o Bigger ood crest does NOT mean a bigger ood 0 Flood lntensityDischargearea where the ood occurs 0 Effects of Flooding 0 Primary effects directly caused by the ood Injury Loss of life Damage caused by swift currents debris and sediment to farms homes buildings roads bridges and communication systems Erosion and deposition of sediment in urban and rural landscapes may also result in loss of soil and vegetation Lecture 13 9 0 Secondary effects disruption of services and systems due to the ood Short term pollution of rivers Hunger and disease Homelessness Possibly res 0 Factors that contribute to ood damage 0 Land use on the oodplain o Magnitude depth and velocity of the water and frequency of ooding Rate of rise and duration of ooding Season Growing season on the oodplain Sediment oad deposit Effectiveness of forecasting warning and emergency systems 0000 o Anthropogenic Factors that contribute to ooding o Inappropriate land use Any kind of land use changes that affect the shape of the channel andor the streams volume of sediment or water may set into motion a series of events that results in a new quotdynamic equilibriumquot 0 Urbanization Sends water to the river much faster than nature Makes the ground impermeable to soak up the water If sewers are blocked you re sitting in a clogged shower 0 Nature and the Extent of Floods o Flooding is one of the most universally experienced natural hazards o In the US oods were the 1 type of disaster during the 20th century 10000 deaths over the course of 100yrs o This number is low compared with developing countries that lack monitoring facilities warning systems and effective disaster relief Adjustment to Food Hazards o Historically particularly in the 19th century people have responded by attempting to prevent the problem 0 They modi ed the stream by creating physical barriers such as dams or evees or by straightening widening and deepening the entire stream so that it would drain the land more efficiently Lecture 13 10 Every new ood control project has the affect of luring more people to come and settle in the oodplain with the false impression that ood hazards are no longer an issue We have yet to build a dam or channel capable of controlling the heaviest runoff and when the water nally does exceed the capacity of the structure the ooding will be merciless In recent years we have begun to accept the fact that the ooding will occur so rather then trying to physically prevent it we are now taking measures to make adjustments that will minimize the damage when the ooding happens 0 Methods of Hazard Adjustment 0 Physical Barriers Construction of concrete levees and oodwalls Potential bene ts are often lost because of the increased development on the oodplain In addition structures constructed many years ago may be in poor condition and incapable of handling the capacity the river currently produces Finally the barriers may actually increase ooding in the long run as they can result in bottlenecking during downstream oods which will induce ooding up stream We have since learned that structural controls must be handled in conjunction with oodplain regulations in order to work properly 0 Retention Ponds Reservoirs to store water for safe release at a later time Lecture 13 11 Paved quot Paved K Temporary storage Direct runoff of runoff in through retention pond storm drain Without use of retention ponds 7 a With use of Runoff gt discharge n Fquot retention ponds o Channelization Straightening deepening widening clearing or lining existing stream channels This can be a good technique in many cases There are numerous areas particularly around urban communities where channelization works beautifully and has little affect the surrounding environment There are a number of factors that must be considered before a channelization project takes place Drainage of wetlands Cutting trees along the stream eliminating shade resulting in damage to aquatic plants and heat sensitive organisms Cutting of hardwood trees on the oodplain eliminates the habitat of many animals Straightening and modifying the stream bed destroy the ow patterns and therefore mess up the feeding and breeding areas for aquatic life 0 Straightening streams and draining wetlands degrades the aesthetic value of a natural area Lecture 13 0 Channel Restoration an alternative Many channelized Channelized stream Naitu rail stream Channel conditions increased water temperatures no shading no cover for fish lite rapid daily and seasonal temperature uctuations reduced ledt material inlput Suitable water temperatures equate s a ing good cover tor fish lite minimal temperature variation abundant leali material input Paolri lle sequences Mostly riFtle Pool silt sandr and tine gravel Rilfle aaarse gravel Sorted graveis provide diversified habitats Far many stream organisms Unsorted gravels reduction in habitats few organisms Pool environment II 5a High flaw High flow Dwelfe wale VEIOCWESK May have stream velocity higher high m POQISJ IQWE l mesh Res nng than some aquatic life can stand areas abundant beneath lbainks behind Few m no remng piaces large rocks etc lRiifer environment Low flaw insufficient depth ot flow during dry season to support fish and other aquatic life Few ilany pools all riflle Sutticient water depth to support Fish and other aquatic life during dry season Copyright 2008 Pearson Prentice Hall Inc 12 streams in urban areas scarcely resemble natural channels Channel restoration uses various techniques in order to create a more natural channel by allowing the stream to meander and provide variable ow conditions fast and shallow ow places alternating with deep and slow ow places Techniques include Cleaning urban waste from the channel Protecting the existing channel banks Allowing the stream to ow freely Making it unlawful to remove trees When necessary replanting native trees and vegetation Use Riprap to control atera bank erosion Lecture 13 13 39 EiHl i EVE Pool c7 c D I D M Trees Location where development of solncl gravel point bar is expected E Riprop If A Aquot Cross section line a a Path of l39TICllll39l currenf d r low How 0 Flood Plain Regulation Flood Insurance and Hazard Mapping 0 When private companies became reluctant to continue to offer ood insurance the federal government took over and created the US National Flood Insurance Program 0 New property owners in special ood hazard areas Floodplains must buy insurance at rates determined on the basis of risk 0 Program is intended to provide short term nancial aid to victims of oods as well as establish long term land use regulations for the nations oodplains Only ood proof building are allowed in the area designated as the 100yr ood area No construction at all is allowed in the area of the ood plain designated as quot20yr oodquot o For a community to join the National Flood Insurance Program it must adopt minimum standards of land use regulation as mapped by the federal Emergency Management area 0 Nearly all communities in ood risk zones in the US have adopted some form of oodplain regulations 0 How big and how frequent o FEMA will gure out the probability of an area being ooded and zone out areas where structures can and cannot be built Lecture 13 14 Patrick River Stream Gauge Data Peak Annual Flow M Magnitude 500 3 Year D39schcrge M R where M 1 is 7 20year Flood lcmsl Yrs the highest Flow I on record 400 f e x R Recurrence E Interval in years 8 300 e I calculated by E RN1 e 39 M 39 339 200 r a for Patrick River N 9 Data 2000 26 7 1394 100 l Extrapolated 2001 100 3 33 beyond data 2002 23 8 1393 01 2 5 10 20 50 100 2003 20 9 11 Recurrence Interval years I Copyright 2008 Pearson Prentice Hall Inc 0 Floodplain Regulation Floodplain only llooclprooledl construction Headway no construction 0 Misc Methods of Hazard Adjustment 0 Flood Proo ng Raising the foundation of a building above ood hazard level Construct ood walls or Earth berms around buildings to seal them from ood waters Using water proof construction for basement walls and windows throughout the building Installing improved drains with pumps to quickly remove water if it enters 0 Relocation Lecture 13 15 Relocating people from the Flood Plains 0 Bottom Line 0 The best approach to minimizing damage in urban areas is oodplain regulation The objective is to obtain the most bene cial use of oodplains while minimizing the ood damage and cost of ood protection Realistically the most effective and practical solution will be a combination of oodplain regulations and physical barriers that result in the fewest amounts of physical modi cations to the river system It is compromise between indiscriminate use of the oodplain resulting in loss of life and tremendous property damage and complete abandonment of the oodplains which gives up a valuable resource
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