Environmental Geology Prof. Steven Dutch Office: LS 463 Phone: 465-2246 Email: [email protected] Home Page: www.uwgb.edu/dutchs.
Download ReportTranscript Environmental Geology Prof. Steven Dutch Office: LS 463 Phone: 465-2246 Email: [email protected] Home Page: www.uwgb.edu/dutchs.
Environmental Geology Prof. Steven Dutch Office: LS 463 Phone: 465-2246 Email: [email protected] Home Page: www.uwgb.edu/dutchs Minerals • Toxins – Hg, Cd, As, etc. • Carcinogens – Asbestos, Silica Sand • Radiological hazards – Uranium and Thorium decay series (U, Th, Ra, Rn, Po) • Hazards arise from: – Bulk Chemistry – Trace impurities – Physical State Igneous Rocks and Volcanoes • Direct volcanic hazards – – – – – – – Lava Flows Ash falls Pyroclastic flows Mudflows Landslides and cone collapse Floods Gases • Climatic effects – Stratospheric ash – Sulfur aerosols • Super-Volcanoes – Magma chamber collapse – Flood basalts Surface Water • Lack of potable water is the single greatest hazard to human health – Women in arid developing regions spend up to 1/3 of their time gathering water – Diarrhea from contaminated water is the single greatest cause of infant mortality. – Aid workers have to fight to convince mothers that diarrhea is not a normal childhood disease • Problems with surface water – Disease organisms – Contamination by pollutants and sewage • Overuse of Surface Water – "Whiskey's for drinking, water's for fighting over." – Owens Valley, California – Aral Sea Ground Water • Mechanics of ground water – – – – Recharge zone Aquifers Aquitards Springs, wetlands and lakes – Artesian systems – Wells – Karst • Human impacts on ground water – Cone of depression – Migration of salt water and contaminants – Contamination of aquifers – Land subsidence – Impact on surface water Soils • No soil, no food. It's that simple. • Soils are complex entities, resulting from the interaction of: – – – – Time Climate Vegetation Drainage • Types of Soils • Soil Erosion – Poor plowing practices – Overgrazing – Deforestation • Other Soil Degradation – Climatically inappropriate farming – Urbanization • Soil preservation approaches – – – – Contour plowing Strip cropping No-till agriculture Reforestation Weathering and Erosion • Floods – River floods – Coastal floods – Dam Failure (Natural or Artificial) • Mass Wasting – Soil Creep – Mudflows – Avalanches – Slumps Deserts and Wind Erosion • Desertification – Expansion of deserts at the margins due to overgrazing and deforestation – "The Bedouin is not the son of the desert, but its father." – North Africa was forested in pre-Roman times – Sub-Saharan Africa • Wind Erosion – – – – – Loess soils feed the world Present-day wind erosion strips topsoil Burial of vegetation or exposure of roots Respiratory hazards Cost of clearing wind-blown sediment from roads Coastal Processes • Storm Surges – Galveston, 1900 – Bangladesh, 1971 – New Orleans, 2005 • Subsidence – Louisiana • Erosion – Effects on property values – Attempts to control Earthquakes • Causes – Plate boundaries – Intraplate • Hazards – “Earthquakes don’t kill people, Buildings kill people” – Tsunami – Landslide – Fire • Hazard Mitigation – Construction – Zoning • Prediction? – Short Term (Precursors) – Long Term (Seismic Gaps, Paleoseismology) Resources • Mineral Resources – Metallic versus non-metallic – Extraction methods – Environmental Impacts • Non-Petroleum energy resources – Coal – Uranium – Geothermal • Petroleum and Natural Gas – Geopolitical and Geological realities – Petroleum production • Non-conventional energy sources – – – – – – Methane hydrates Tar sands Oil shales Oil mining Hot dry rock geothermal Deep Earth gas hypothesis Extraterrestrial Hazards • • Can we predict impacts? The Torino Scale of Impact Hazard – Named for the city in Italy, not a person – Assesses both probability of event and potential effects of impact – Therefore not completely consistent. • Likely impact scenarios – Atmospheric impact and air burst (Tunguska, 1908) – Surface impact causing local damage – Surface impact with 100 km damage radius – Surface impact with 1000 km damage radius – Surface impact with global effects • • What happens during impact Environmental Effects – – – – – – – Radiant heat and flash burns Blast wave Seismic waves Tsunami Ejecta Stratospheric dust Liberated volatiles (carbon dioxide, sulfur, methane) – Impact volcanism - a myth Military Impacts on the Environment • Clausewitz: "War is policy carried on by other means." – All war is inherently political – The last general who was utterly unconstrained was Napoleon • • • • • Incidental (collateral) damage Modifications to facilitate own operations Modifications to impede enemy Strategic Modifications Environmental Terrorism Exponential Growth • Invest one cent at 1% interest per year, compounded annually, in the year 1 AD • By now it would be worth $.01 x (1.01)2011 = $4,900,000.00 • At 2%: $1,895,592,883,959,335.15 or 30 times the total GDP of the earth • At $1000 per ounce = 58,952,939 tons of gold. • Total amount of gold ever mined is around 150,000 tons. You could not be paid in gold. Exponential Growth • Doubling time = 72 years / % annual growth rate – – – – 4% = 18 years 3% = 24 years 2% = 36 years 1% = 72 years • Implications for Earth – All exponential growth, no matter how low the rate, eventually becomes huge. – You can't get an infinite amount of anything (like people) into a finite space – You can't get an infinite amount of anything (like resources) out of a finite space – Nothing can grow forever Exponential Growth • At 2% per year, global population will be: – – – – – 12 billion in 2041 24 billion in 2077 48 billion in 2113 One person per square meter (land and sea) in 2594 Equal to the mass of the earth in 3596 • What will limit growth? – Natural methods (famine, disease and war) – Imposed by society (China's one-child policy) – Personal preference (Demographic Transition) • No amount of environmental awareness will matter unless population growth stops Exponential Growth • Impacts on Earth – – – – – Diversion of primary capacity to feed humans (now at least 25%) Destruction and fragmentation of habitat Direct consumption of animals and plants for food and fuel Increased degradation of land by erosion Increased hazard to humans as populations in dangerous terrain increase • Prognosis – Humans will probably always operate in crisis management mode (not dealing with a problem always offers immediate returns) – Sooner or later we will miscalculate our ability to avert disaster One Last Demographic Effect of Population Growth Population Equals Regulation