Contents
CHAPTER 1 - Approaching the Subsurface
- What Are the Options?
- Some fundamental Considerations
- Defining Objectives
- Limitations
- The Advantage of Multiple Methods
CHAPTER 2 - Seismic Exploration: Fundamental Considerations
- SEISMIC WAVES AND WAVE PROPAGATION
- Wave Terminology
- Elastic Coefficients
- Seismic Waves
- Seismic Wave Velocities
- RAY PATHS IN LAYERED MATERIALS
- Huygens' Principle
- Fermat's Principle
- Reflection
- Refraction
- Snell's Law
- Critical Refraction
- Diffraction
- Wave Arrivals at the Surface
- WAVE ATTENUATION AND AMPLITUDE
- Spherical Spreading
- Absorption
- Energy Partitioning
- Additional Factors
- ENERGY SOURCES
- Source Types
- Source Considerations
- SEISMIC EQUIPMENT
- Signal Detection
- Signal Conditioning
- Signal Recording
- SUMMARY
- PROBLEMS
- REFERENCES CITED
CHAPTER 3 - Seismic Exploration: The Refraction Method
- A HOMOGENEOUS SUBSURFACE
- A SINGLE SUBSURFACE INTERFACE
- Derivation of Travel-Time Equation
- Analysis of Arrival Times
- Determining Thickness
- Crossover Distance
- Critical Distance
- Constructing a Travel-Time Curve from a Field Seismogram
- Using REFRACT
- The Mohorovicic Discontinuity
- TWO HORIZONTAL INTERFACES
- Derivation of Travel-Time Equation
- Determining Thickness
- Critical Distance
- Analyzing a Second Field Seismogram
- MULTIPLE INTERFACES
- DIPPING INTERFACES
- Analyzing the Problem
- Derivation of a Travel-Time Equation
- Determining Thickness
- MULTIPLE DIPPING INTERFACES
- Travel-Time Equation
- Analyzing Field Seismograms
- THE NON-IDEAL SUBSURFACE
- Hidden Zones: The Low-Velocity Layer
- Hidden Zones: The Thin Layer
- Laterally Varying Velocity
- Interface Discontinuities
- THE DELAY-TIME METHOD
- OTHER METHODS
- Wave Front Method
- Ray Tracing and the Generalized Reciprocal Method
- FIELD PROCEDURES
- Site Selection and Planning Considerations
- Equipment Considerations
- Geophone Spread Geometries and Placements
- Corrections to Data
- APPLICATIONS USING SEISMIC REFRACTION
- Whately, Massachusetts
- Southeastern New Hampshire
- Waste Disposal Site
- Maricopa Area, Arizona
- PROBLEMS
- REFERENCES CITED
- SUGGESTED READING
CHAPTER 4 - Seismic Exploration: The Reflection Method
- A SINGLE SUBSURFACE INTERFACE
- Using REFLECT
- Derivation of Travel-Time Equation
- Analysis of Arrival Times
- Normal Move-Out
- Determining Velocity and Thickness
- Applying the x2 - t2 Method to a Field Seismogram
- MULTIPLE HORIZONTAL INTERFACES
- The Dix Equation
- Determining Velocities
- Determining Thicknesses
- Further Discussion of the Dix Method
- Analyzing a Field Seismogram Containing Multiple Reflections
- DIPPING INTERFACE
- Derivation of Travel-Time Equation
- Determining Dip, Thickness, and Velocity
- Determining Dip, Thickness, and Velocity-Another Approach
- A Return to Normal Move-Out
- Determining Dip, Thickness, and Velocity-Yet Another Approach
- ACQUIRING AND RECOGNIZING REFLECTIONS FROM SHALLOW INTERFACES
- The Optimum Window
- Multiple Reflections
- Diffractions
- COMMON FIELD PROCEDURES
- Equipment Considerations
- Geophone Spreads
- Split Spread
- Common Offset
- Common Depth Point
- COMPUTER PROCESSING OF REFLECTION DATA
- The Static Correction
- Correcting for Normal Move-Out
- Velocity Analysis A
- Velocity Analysis B
- Velocity Analysis C
- Stacking CDP Gathers
- Migration
- Waveform Adjustments
- Seismic Sections: Time Sections and Depth Sections
- APPLYING THE SEISMIC REFLECTION METHOD
- Whately, Massachusetts
- Meers Fault, Oklahoma
- Cavity Detection
- PROBLEMS
- REFERENCES CITED
- SUGGESTED READING
CHAPTER 5 - Electrical Resistivity
- INTRODUCTION
- Applied Currents
- Natural Currents
- A Brief History
- Chapter Goals
- BASIC ELECTRICITY
- CURRENT FLOW IN A HOMOGENEOUS, ISOTROPIC EARTH
- Point Current Source
- Two Current Electrodes
- Two Potential Electrodes
- A SINGLE HORIZONTAL INTERFACE
- Current Distribution
- Current Flow Lines and Current Density
- Apparent Resistivity
- Qualitative Development of the Resistivity Pattern over a Horizontal Interface
- Quantitative Development of the Resistivity Pattern over a Horizontal Interface
- Using RESIST
- MULTIPLE HORIZONTAL INTERFACES
- VERTICAL CONTACT
- Constant-Spread Traverse
- Expanding-Spread Traverse
- TWO VERTICAL CONTACTS, HEMISPHERICAL STRUCTURES, AND DIPPING INTERFACES
- Two Vertical Contacts
- Hemispherical Structures
- Dipping Interfaces
- FIELD PROCEDURES
- Equipment
- Electrode Configurations
- Surveying Strategies
- Other Considerations
- QUANTITATIVE INTERPRETATION OF APPARENT RESISTIVITY CURVES
- Electrical Resistivities of Geologic Materials
- Empirical Methods
- Analytical Methods-Curve Matching
- Analytical Methods-Automated Curve Matching
- APPLICATIONS OF ELECTRICAL RESISTIVITY SURVEYING
- Applications Related to Aquifers
- Applications Related to Contamination
- Applications in Mapping Karst and Geologic Structures
- Other Applications
- OTHER ELECTRICAL METHODS
- Induced Potential (IP)
- Spontaneous Potential (SP)
- Telluric and Magnetotelluric Methods
- PROBLEMS
- REFERENCES CITED
- SUGGESTED READING
CHAPTER 6 - Exploration Using Gravity
- FUNDAMENTAL RELATIONSHIPS
- Gravitational Acceleration
- MEASURING GRAVITY
- Relative Measurements Using a Pendulum
- Relative Measurements Using a Gravimeter
- Absolute Measurements
- International Gravity Standardization Net 1971 (IGSN71)
- ADJUSTING OBSERVED GRAVITY
- Variation in g as a Function of Latitude
- Correcting for the Latitude Effect
- Elevation Correction 1: The Free-Air Correction
- Elevation Correction 2: The Bouguer Correction
- Elevation Correction 3: The Terrain Correction
- The Isostatic Anomaly
- BASIC FIELD PROCEDURES
- Drift and Tidal Effects
- Establishing Base Stations
- Determining Elevations
- Determining Horizontal Position
- Selecting a Reduction Density
- Survey Procedure
- GRAVITY EFFECTS OF SIMPLE GEOMETRIC SHAPES
- Rock Densities
- Gravity Effect of a Sphere
- Gravity Effect of a Horizontal Cylinder
- Gravity Effect of a Vertical Cylinder
- Gravity Effect of an Inclined Rod
- Gravity Effect of a Horizontal Sheet
- GRAVMAG
- ANALYZING ANOMALIES
- Regionals and Residuals
- Trend Surfaces
- Upward and Downward Continuation
- Second Derivatives
- Filtering
- GRAVITY INTERPRETATION
- Half-Maximum Technique
- Second Derivative Techniques
- Revisiting Some Bouguer Anomaly Values
- APPLICATIONS OF THE GRAVITY METHOD
- Bedrock Depths
- Subsurface Voids
- Landfill Geometry
- PROBLEMS
- REFERENCES CITED
- SUGGESTED READING
CHAPTER 7 - Exploration Using the Magnetic Method
- FUNDAMENTAL RELATIONSHIPS
- Magnetic Force
- Magnetic Field Strength
- Magnetic Moment
- Intensity of Magnetization
- Magnetic Susceptibility
- Magnetic Potential
- THE EARTH'S MAGNETIC FIELD
- Field Elements
- Dipolar Nature of the Earth's Field
- Variations of the Earth's Field
- Dipole Equations
- MEASURING THE MAGNETIC FIELD
- Flux-Gate Magnetometer
- Proton-Precession Magnetometer
- Total-Field Anomalies
- BASIC FIELD PROCEDURES
- Magnetic Cleanliness
- Diurnal Corrections
- Elevation Corrections
- Correcting for Horizontal Position
- MAGNETIC EFFECTS OF SIMPLE GEOMETRIC SHAPES
- Rock Susceptibilities
- Magnetic Effect of an Isolated Pole (Monopole)
- Magnetic Effect of a Dipole
- Magnetic Effect of a Sphere
- Magnetic Effect of Thin, Horizontal Sheets
- Magnetic Effects of Polygons with Infinite Strike Length (Using GRAVMAG)
- INTERPRETATION OF MAGNETIC DATA
- Disadvantages and Advantages
- Quantitative Interpretation Techniques
- Half-Maximum Techniques
- Slope Methods
- Computer Modeling
- APPLICATIONS OF THE MAGNETIC METHOD
- Archaeological Surveys
- Detection of Voids and Well Casings
- Defining Landfill Geometry
- PROBLEMS
- REFERENCES CITED
- SUGGESTED READING
CHAPTER 8 - Electromagnetic Surveying
- ELECTROMAGNETIC WAVES
- Wavelengths
- AC/DC
- Electrical Properties of Geologic Materials
- Electrical Resistivity and Conductivity
- Dielectric Properties
- Absorption and Attenuation
- EM SOUNDING
- Near-Field Continuous-Wave Methods of Frequency Domain Electromagnetics (FDEM)
- Moving Transmitter-Plus-Receiver System (Slingram)
- Noncontacting Ground Conductivity Measurements
- Other FDEM systems
- Time Domain Electromagnetics (TDEM)
- EM FIELD TECHNIQUES
- Profiling versus Sounding
- Sounding
- Profiling
- Interpretation
- GROUND PENETRATING RADAR
- Radar Velocity
- Data Acquisition
- GPR Velocity Analysis
- Burial of Known Object
- Walkaway Test
- Diffraction Hyperbola
- APPLICATIONS OF ELECTROMAGNETIC SURVEYING
- Archaeological Surveys
- Aztec Ruins, New Mexico
- Ceren, El Salvador
- Geologic Applications
- Snow and Ice Mapping
- Environmental and Engineering Applications
- PROBLEMS
- REFERENCES CITED
- SUGGESTED READING
APPENDIXES
- A Instructions for using REFRACT
- B Instructions for using REFLECT
- C Instructions for using RESIST
- D Instructions for using GRAVMAG
- E Instructions for using DIFFRACT
REFERENCES UTILIZED
Copyright © 2005, W. W. Norton & Company. All rights reserved.
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