ENVIRONMENTAL GEOLOGY GL 2001.6 This course introduces the concepts of environmental geology within an The course reviews material previously studied in first and second year m for resources, their development and location both globally and within th Geological Hazards are then evaluated; both natural and manmade. Final issues are addressed. Environmental Geology What is it? Reading list Course Text Book? Woodcock, N (1994) " Geology and Environment in Britain and I Press Other Text? Coats, D. R. (1981) "Environmental Geology" John Wiley? Keller, E. A. (1976) "Environmental Geology" Merill? Tank, R. (1973) "Focus on Environmental Geology" Oxford Uni.
Course Outline? Background? Resources? Natural Geologic Hazards? Manmade Hazards - Waste Disposal Background? Environmental Geology - What is it?? Course Concepts Earth System Sciences "The Earth's Past as a Guide to the Earth's Future." Woodcock (1995)? Careers? Links with other Courses Resources? What are they?? Renewable/Nonrenewable? Geologic Influence on Resources - UK resources? Review of Previous courses - Metallic, Non-metallic, water? Energy Resources - Nuclear? Energy Resources - Renewable Geologic Hazards - Causes, Risks, Prediction, Mitigation? Earthquakes? Landslides? Subsidence? Radon? Volcanoes Man-made Hazards - Waste Disposal
? Managed vs. Un-managed Disposal? History of Waste Disposal? Types of Waste Disposal? Problems Nomenclature Earth Sciences - the study of the lithosphere and inner Earth Earth System Sciences - the study of interactions of all environmental com lithosphere, hydrosphere, biosphere, atmosphere, magnetosphere, (politic Lithosphere - crust and upper mantle Hydrosphere - all the waters on face of Earth and in crust Biosphere - all regions occupied or potentially occupied by living organis Atmosphere - the continuous gaseous envelope surrounding the Earth Magnetosphere - the space pervaded by the Earth's magnetic field Some Environmental Issues Today? Fossil Fuels vs. Nuclear Fuels?? Sensitive Economic Extraction of Resources? Recycle vs. Energy Consumption? Hazardous discharge and biodiversity? Old waste disposal sites and SSSI's? When is contamination safe?? Prediction of Geologic hazards? Global warming or just a lot of hot air? read Mellanby, K (1992) "Waste and Pollution, the Problem for Britain". Resources - What are they? Reference during this course is made extensively to the material taught b and MacNeill during the first year courses on metallic and non-metallic m references will be made to the first year course on groundwater (G1001). Non-renewable Resources - review previous courses Geology Courses
? Base metals - Fig WES G1001? Precious metals - Fig WES G1001? Building material - Fig GMcN G1001? Hydrocarbons - Fig GMcN G1001, Oil and Gas Resources, USGS? Nuclear Renewable Resources (Renewable energy, CREST) Renewable? Water (CRB G1001)? Solar? Geothermal? Biomass(biomass, CREST)? Wind(Wind Power, CREST) Resource Geology of Britain? Global and UK consumption? Global and UK reserves? Resources and their locations in the British Isles? Energy consumption in the UK? Energy resource distribution in the UK To find out more about energy in the UK and elsewhere in the World vis sites: Energy and the environment at; http://www.wam.umd.edu/~tfagan/enrgyenv.html EPA - US Environmental Protection Agency; http://www.epa.gov/ Renewable Energy; http://www.eren.doe.gov/ Global change; http://www.usgcrp.gov/ UK National Energy Foundation; http://www.natenergy.org.uk/
UK Nuclear Industry http://www.users.zetnet.co.uk/n-base/ http://www.ukaea.org.uk/ UK Solar Energy Society; http://www.demon.co.uk/tfc/uk-ises.html Energy Resources Potential Renewable Energy resources for the UK? Hydroelectric 0.7%? Wave 6%? Solar 6%? Tidal 6%? Biomass 13%? Wind 22% Nuclear Energy - non-renewable energy? Resources? World reserves concentrated in few countries. China and former S aside present levels of consumption will last only 50 years.? World resources estimated at 1860 thousand tonnes Nuclear Energy - World Reserves Nuclear Energy - Fuel Cycle Geothermal Energy - Renewable/Partially Renewable Types of Geothermal Energy:
Geothermal Aquifer -? low enthalpy system? average heat flow? high heat gradient? low thermal conductivity e.g. mudstones? few km deep,? heat exchange by pumping hot saline water Hyperthermal Systems (Geothermal, US DOE)? high enthalpy? high heat flow (300mWm-2) e.g. intrusions? ground water directly heated and moved by hydrothermal convec? water trapped and taped via fracture system? water steams on release of pressure? renewable on human time scale due to great heat Geothermal Hot-dry Rock (e.g. Cornwall)? higher heat production than average? pump water into induced fracture system? problems with keeping fracture system active? may be important for the future but technically difficult Hazards? Natural Hazards? Man-made Hazards Study Methods? Causes - identification of processes? Risk areas - mapping hazard areas? Prediction - monitoring hazard development? Mitigation - hazard engineering Natural Geologic Hazards? Earthquakes? Landslides? Subsidence? Radon? Volcanic
Landslides Types of Landslide (fig)? fall - rock, topples? creep? flow? slide - rotational, debris, mud, rock? slump - sagging? compound Causes (fig)? loading of head - sedimentation, man-made load? strength reduction - weathering, bioremoval? wetting? undercutting? change in pore pressure? ground instabilities from external sources - earthquakes Landslides - Landslide Classification The National Landslide Review Table insert Groups of Landslide failure? First time Failure - previously unsheared ground. Large rapid disp Holbeck Hall Slide. (case history)? Failures on Pre-existing Shear Surfaces - surfaces often non-lands slopes activated by inappropriate earthworks, Aberfan, 1966. (vid? Reactivation of Previous Slips - new movements on pre-existing s Mam Tor)? Seismic Induced Slips - all of the above induced by high seismic (see: Auburn Dam - USGS) Risk Areas? steep slopes? non vegetated areas? lose soil areas? most coastal areas? high seismic potential areas
For further information on hazard risk areas and prediction see Hazards - lanslides home page, USGS Prediction? surface/subsurface geological mapping (fig)? visual inspection - slope analysis (fig)? water levels? tilt meters? strain gauges? passive seismic monitoring Mitigation? lower moisture content (fig)? reduce slope angles? construction of artificial barriers
Subsidence subsidence - downward displacement of surface material caus or artificial removal of underlying support (collapse) or by co ground (consolidation) disaster when this is rapid Subsidence hydrocompaction - reduction in dry strength of material by addition of w evident in sediments with high void ratios and a clay content of approxim Piping - subsurface flow of water under high hydraulic heads. Erodes cha Karsting - solution of cavities in (mainly) limestones Mantled Karsts - layer of soil over limestone karst masks presence of kar Thermokarst - karsting in regions with permanently frozen ground. Diffe of subsurface. Volcanokarst - piping in volcanic terrain Consolidation
consolidation - natural compression of saturated sediment or influence of static load primary consolidation - initial stress causes water expulsion, c material, usually rapid event secondary consolidation - adjustment of internal structure, fu compression, usually long term event
Effective stress - (Terzaghi, 1936) Subsidence - High Risk Areas? plate boundaries? carbonate geology areas? mining areas Prediction? surface and sub-surface geology mapping? large-scale strain guages? precise geodetic levelling - satelite surveying?? cavity detection using geophysical methods
? mapping man-made hazards - underground mining, (Case Histori Glenrothes practical class) Mitigation? subsidence risk maps? building regulations? fluid injection - repressurization of the ground