An to Applied and Environmental Geophysics 2nd Edition John M. Reynolds Reynolds International Ltd
Preface to the 2 na Edition Acknowledgements 1 1.1 1.2 1.3 1.4 1.5 What are 'applied' and 'environmental' geophysics? Geophysical methods Matching geophysical methods to applications Planning a geophysical survey 1.4.1 General philosophy 1.4.2 Planning strategy 1.4.3 Survey constraints Geophysical survey design 1.5.1 Target identification 1.5.2 Optimum line configuration and survey dimensions 1.5.3 Selection of station intervals 1.5.4 Noise 1.5.5 Position fixing 1.5.6 Data analysis 2 Gravity Methods 2.1 2.2 2.3 2.4 2.5 Physical basis 2.2.1 Theory 2.2.2 Gravity units 2.2.3 Variation of gravity with latitude 2.2.4 Geological factors affecting density Measurement of gravity 2.3.1 Absolute gravity 2.3.2 Relative gravity Gravity meters 2.4.1 Stable (static) gravimeters 2.4.2 Unstable (astatic) gravimeters 2.4.3 Marine and airborne gravity systems Corrections to gravity observations. 2.5.1 Instrumental drift 2.5.2 Tides xi xiii 1 l 3 5 5 5 5 7 9 9 9 11 13 15 16 19 19 19 19 20 20 22 24 24 25 26 27 27 31 34 34 34
4.4 4.5 4.6 4.3.1 Reflection and transmission of normally incident rays 4.3.2 Reflection and refraction of obliquely incident rays 4.3.3 Critical refraction 4.3.4 Diffractions Loss of seismic energy 4.4.1 Spherical divergence or geometrical spreading 4.4.2 Intrinsic attenuation 4.4.3 Scattering Seismic energy sources 4.5.1 Impact devices 4.5.2 Impulsive sources 4.5.3 Explosive sources 4.5.4 Non-explosive sources 4.5.5 High-resolution waterborne sources 4.5.6 Vibrators 4.5.7 Animals Detection and recording of seismic waves 4.6.1 Geophones and accelerometers 4.6.2 Hydrophones and streamers 4.6.3 Seismographs 5 Seismic Refraction Surveying 5.1 5.2 5.3 5.4 5.5 General principles of refraction surveying 5.2.1 Critical refraction 5.2.2 Field survey arrangements Geometry of refracted raypaths 5.3.1 Planar interfaces 5.3.2 Irregular (non-planar) interfaces Interpretational methods 5.4.1 Phantoming 5.4.2 Hagedoorn plus-minus method 5.4.3 Generalised reciprocal method (GRM) 5.4.4 Hidden-layer problem 5.4.5 Effects of continuous velocity change 5.4.6 Seismic refraction ' software Applications and case histories 5.5.1 Rockhead determination for a proposed waste disposal site 5.5.2 Location of a buried doline 149 150 151 151 152 152 153 154 154 155 157 159 159 162 163 166 169 170 171 177 179 179 179 179 181 182 182 185 186 187 188 190 191 192 193 193 193 197
5.6 5.5.3 5.5.4 5.5.5 5.5.6 5.5.7 Assessment of rock quality Landfill investigations Acid-tar lagoons Static corrections Locating buried miners Shear wave methods 5.6.1 5.6.2 5.6.3 Ground stiffness profiling Multichannel Analysis of Shear Waves (MASW) Earthquake hazard studies Seismic Reflection Surveying 6.1 6.2 6.3 6.4 6.5 6.6 Reflection surveys 6.2.1 6.2.2 6.2.3 6.2.4 6.2.5 6.2.6 General considerations General reflection prindples Two-dimensional survey methods Three-dimensional surveys Vertical seismic profiling (VSP) Cross-hole seismology: tomographic imaging Reflection data processing 6.3.1 Preprocessing 6.3.2 Static corrections (field statics) 6.3.3 Convolution and deconvolution 6.3.4 Dynamic corrections, velocity analyses and stacking 6.3.5 Filtering 6.3.6 Migration Correlating seismic data with borehole logs and cones 6.4.1 Sonic and density logs, and synthetic seismograms 6.4.2 Correlation with cone penetration testing Interpretation 6.5.1 Vertical and horizontal resolution 6.5.2 Identification of primary and secondary events 6.5.3 Potential interpretational pitfalls Applications 6.6.1 High-resolution seismic profiling on land 6.6.2 Seismic reflection surveys for earthquake prediction studies 6.6.3 High-resolution seismic profiling over water 199 201 203 205 207 208 208 211 215 217 217 217 217 218 219 221 224 225 228 229 230 233 236 241 243 246 246 247 250 250 252 256 257 257 265 266
6.6.4 Geophysical diffraction tomography in palaeontology 6.6.5 Forensic seismology 7 Electrical Resistivity Methods 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 Basic principles 7.2.1 True resistivity 7.2.2 Current flow in a homogeneous earth Electrode configurations and geometric factors 7.3.1 General case 7.3.2 Electrode configurations 7.3.3 Media with contrasting resistivities Modes of deployment 7.4.1 Vertical electrical sounding (VES) 7.4.2 Automated array scanning 7.4.3 Electrical resistivity tomography (ERT) 7.4.4 Constant separation traversing (CST) 7.4.5 Field problems Interpretation methods 7.5.1 Qualitative approach 7.5.2 Master curves 7.5.3 Curve matching by computer 7.5.4 Equivalence and suppression 7.5.5 Inversion and ' deconvolution 7.5.6 Modelling in 2D and 3D ERT applications and case histories 7.6.1 Engineering site investigations 7.6.2 Groundwater and landfill surveys 7.6.3 Mineral exploration 7.6.4 Glaciological applications Mise-a-la-masse (MALM) method 7.7.1 Mineral exploration 7.7.2 Civil engineering pile testing 7.7.3 Study of tree roots 7.7.4 Groundwater flow Leak detection through-artificial membranes 8 Spontaneous (Self) Potential Methods 8.1 8.2 8.3 Occurrence of self-potentials Origin of self-potentials 8.3.1 Electrokinetic Dotentials 283 286 289 289 289 289 292 293 293 294 298 301 301 303 306 307 308 311 311 313 314 317 318 321 326 326 330 333 333 336 338 341 344 344 346 349 349 349 349 350
8.3.2 Electrochemical potentials 8.3.3 Mineral potentials 8.4 Measurement of self-potentials 8.5 Corrections to SP data 8.6 Interpretation of self-potential anomalies 354 8.6.1 Qualitative interpretation 354 8.6.2 Quantitative interpretation 355 8.7 Applications and case histories 357 8.7.1 Geothermal exploration 357 8.7.2 Mineral exploration 359 8.7.3 Hydrogeology 361 8.7.4 Landfills and contaminant plumes.363 8.7.5 Leak detection 364 8.7.6 Mapping mine shafts 370 8.8 Electrokinetic (EK) surveying 371 9 Induced Polarisation 373 9.1 373 9.2 Origin of induced polarisation effects 374 9.2.1 Grain (electrode) polarisation. 374 9.2.2 Membrane (electrolytic) polarisation' 375 9.2.3 Macroscopic processes 375 9.2.4 Ionic processes 376 9.3 Measurement of induced polarisation 376 9.3.1 Time-domain measurements 376 9.3.2 Frequency-domain measurements 377 9.3.3 Spectral IP and complex resistivity 379 9.3.4 Noise reduction and electromagnetic coupling 381 9.3.5 Forms of display of IP data 382 9.3.6 Inversion and fitting dispersion spectra 383 9.4 Applications and case histories 384 9.4.1 Base metal exploration 384 9.4.2 Hydrocarbon exploration 389 9.4.3 Geothermal surveys 390 9.4.4 Groundwater investigations 391 9.4.5 Environmental applications 392 9.4.6 Geological investigations 398 10 Electromagnetic Methods: and Principles 403 10.1 403 10.1.1 Background 403 10.1.2 Applications 404
11 10.2 10.3 10.4 10.5 10.1.3 Types of EM systems Principles of EM surveying 10.2.1 Electromagnetic waves 10.2.2 Polarisation 10.2.3 Depth of penetration of EM radiation Airborne EM surveying 10.3.1 Background 10.3.2 Frequency-domain EM (FEM) 10.3.3 Time-domain EM (TEM) 10.3.4 Airborne VLF-EM Seaborne EM surveying 10.4.1 Background 10.4.2 Details of marine EM systems Borehole EM surveying Electromagnetic Methods: Systems and Applications n.i 11.2 11.3 Continuous-wave (CW) systems 11.2.1 Tilt-angle methods 11.2.2 Fixed-source systems (Sundberg, Turam) 11.2.3 Moving-source systems 11.2.4 Interpretation methods 11.2.5 Applications and case histories Pulse-transient (TEM) or time-domain (TDEM) EM systems 11.3.1 TDEM/TEM surveys 11.3.2 Data processing and interpretation of TEM surveys 11.3.3 Applications and case histories 404 407 407 410 411 411 411 412 414 418 418 418 421 426 431 431 431 431 432 433 437 441 467 467 468 470 12 Electromagnetic Methods: Systems and Applications II 495 12.1 Very-low-frequency (VLF) methods 495 12.1.1 495 12.1.2 Principles of operation 495 12.1.3 Effect of topography on VLF observations 498 12.1.4 Filtering and interpretation of VLF data 498 12.1.5 Applications and case. histories 499 12.2 The telluric method 502 12.2.1 Principles of operation 502 12.2.2 Field measurements 503 12.3 The magnetotelluric (MT) method 505 12.3.1 Principles of operation 505 12.3.2 Field measurements 505 12.3.3 Interpretation methods 507
12.4 12;3.4 Applications and case histories Magnetic Resonance Sounding (MRS) 12.4.1 Principles of operation 12.4.2 Field measurements 12.4.3 Interpretation methods 12.4.4 Case histories 509 519 519 522 525. 525 13 to Ground-Penetrating Radar 13.1 13.2 13.3 13.4 13.5 13.6 13.7 Principles of operation Propagation of radiowaves 13.3.1 Theory 13.3.2 Energy loss and attenuation 13.3.3 Horizontal and vertical resolution Dielectric properties of earth materials Modes of data acquisition 13.5.1 Radar reflection profiling 13.5.2 Wide-angle reflection and refraction (WARR) sounding 13.5.3 Trans-illumination or radar tomography Data processing 13.6.1 During data acquisition 13.6.2 Wide-angle reflection and refraction (WARR) sounding 13.6.3 Post-recording data processing Interpretation techniques 13.7.1 Basic interpretation 13.7.2 Quantitative analysis 13.7.3 Interpretational pitfalls 14 Ground-Penetrating Radar: Applications and Case Histories 14.1 14.2 14.3 Geological mapping 14.1.1 Sedimentary sequences 14.1.2 Lacustrine environments 14.1.3 Geological faults Hydrogeology and groundwater contamination 14.2.1 Groundwater contamination 14.2.2 Mapping the water table Glaciological applications 14.3.1 Polar ice sheets 14.3.2 Snow stratigraphy and crevasse detection 14.3.3 Temperate glaciers 14.3.4 Glacial hazards 535 535 537 539 539 540 544 546,552 552 553 553 554 556 556 557 560 560 562 562 565 565 565 567 570 571 571 576 578 578 581 583 586
14.4 Engineering applications on manmade structures 587 14.4.1 Underground storage tanks (USTs), pipes and cables 588 14.4.2 Transportation infrastructure 592 14.4.3 Dams and embankments 594 14.4.4 Golf courses 597 14.5 Voids within manmade structures 599 14.5.1 Voids behind sewer linings 600 14.5.2 Buried crypts and cellars. 600 14.5.3 Coastal defences 602 14.6 Archaeological investigations 603 14.6.1 Roman roads 603 14.6.2 Historical graves 603 14.6.3 Buried Roman structures 604 14.6.4 Burial mounds 605 14.7 Forensic uses of GPR 607 14.8 Wide-aperture radar mapping and migration processing 607 14.9 Borehole radar 609 14.9.1 Hydrogeological investigations 612 14.9.2 Mining 613 14.10 14.11 UXO and Animals 15 Radiometrics 15.1 15.2 15.3 15.4 15.5 15.6 landmine detection Natural radiation 15.2.1 Isotopes 15.2.2 a and fi particles, and y radiation 15.2.3 Radioactive decay series and radioactive equilibria 15.2.4 Natural gamma-ray spectra Radioactivity of rocks Radiation detectors 15.4.1 15.4.2 15.4.3 15.4.4 15.4.5 15.4.6 Geiger-MLUler counter Scintillometers Gamma-ray spectrometers Radon detectors Seaborne systems Borehole logging tools Data correction methods 15.5.1 Detector calibration 15.5.2 Thorium source test 15.5.3 Dead time and live time 15.5.4 Geometric corrections 15.5.5 Environmental factors 15.5.6 Compton scattering 15.5.7 Terrain clearance corrections 15.5.8 Radio-element ground concentrations Radiometric data presentation 617 618 625 625 625 625 626 626 627 628 628 628 629 630 630 631 632 633 633 633 633 633 634 634 634 635 635
15.7 Case histories 15.7.1 Mineral exploration 15.7.2 Engineering applications 15.7.3 Soil mapping 15.7.4 Nuclear waste disposal investigations ; 636 636 638 639 642
Appendix 645 References 649 Index 681