Geophysical Methods for Geologists, Environmental Scientists and Civil Engineers

Chapter 1 Introduction: Philosophy and basic principlesA practical manual for engineers, environmental scientists and geologists: the book shows how to decide if a geophysical survey is a cost-effective method for solving a sub-surface problem, how to choose which method to use, how to quality assure the results and how to assess the validity of the interpretation. The geological, environmental and engineering problems that geophysics can help to solve - and those which it cannot!The trade-off between resolution and depth of imagingDefining the reliability of the sub-surface image Chapter 2 Physical properties of rocks and sediments: these are what makes geophysics work!Exploring the ranges of the physical properties of rocks and sediments and their sensitivity to the geophysical methods which can resolve them: the solid matrix, the plastic (clay) component and the fluid component of rocks Chapter 3 Geophysical surveying methods for different environments: these are the methods which are available to you!Airborne techniquesSurface techniquesThe land surfaceRiver and flood plainBeach and inter-tidal zoneShallow marineDeep seaSub-surface techniquesBorehole loggingBorehole-to-borehole measurements Vertical seismic profiling Chapter 4 Specification and implementation of the geophysical survey: how to choose the correct method and keep a close eye on the contractorsDefining the environmental or engineering problemAnalysing the physical properties, dimensions and depths of burial of the sub-surface targetsIs a geophysical technique appropriate? It may be more cost-effective to auger or drill a few boreholes!Using interactive spreadsheets to define appropriate geophysical methods for the targetDesigning the size and sampling interval of the surveyCosting the surveySupervising the field acquisitionQuality assurance of the raw field data Chapter 5 Processing the raw field dataHow to remove interference which degrades the quality and accuracy of the target geophysical dataQuality assurance of processing: have the geophysical data been under- or over-processed? Chapter 5 Inversion of the survey: the geophysical modelWhat does inversion mean?Commercial computer inversion packagesStraightforward EXCEL inversion routinesSimple rules-of-thumb for checking computer inversionHow to assess the accuracy, stability and resolution of the inversion Chapter 6 Turning the geophysical model into a geological, environmental or engineering solutionDetermining the sub-surface physical/geological/engineering relationshipsAssessing the reliability, stability and accuracy of the relationshipsVisualisation of the geological/environmental/engineering solutionAssessing the stability, reliability and accuracy of the solution Chapter 7 Imaging sub-surface rocks - principles and short case historiesGeological mappingSite investigationRock mass assessmentLocation of natural cavities and mineshaftsCoastal and near-shore investigationsArchaeological Investigations Chapter 8 Imaging fluids within the rocks - principles and short case historiesGroundwater explorationGroundwater pollutionLandfill sites: location, consolidation of the fill, leakage of leachates, gas detection. Derelict and contaminated land assessment. Investigations in urban areas. Chapter 9 Full case histories - from the initial problem to the final report Bath Spa Thermal Water ProjectA case study of an integrated geophysical survey from the initial meeting of client and consultants to the presentation of the final report to the client and a public meeting. Additional Case Histories from USA and Canada Chapter 10 Future trends in exploration geophysics: the developments we expect (hope!) will come on-stream during the next ten years. References Appendix 1 Specification and Implementation of a Geophysical Survey