GEOPHYSICS PART
Book List and Preparation Strategy: (Blue=Topics Prepared , Red= Topics Not Prepared)
For students pursuing/completed their master's degree in geophysics discipline, they must concentrate mainly on Part-A of Geophysics paper-I, II & III .
As students with master's degree in physics are also eligible for this exam; my suggestion to them is to concentrate mainly on Part-B of each paper (i.e. physics portion) .
GENERAL ENGLISH: No dedicated study needed. Just do the last four year papers given above. That will be sufficient.
Geophysics Paper-I Part-A:
a.Solid Earth Geophysics :
Syllabus: Introduction to Geophysics its branches and relationship with other sciences. Solar system, its origin,characteristics of planetary members, Earth; its rotation and figure. Age of earth & various methods of determination. Tectonics and Geodynamics, Thermal history and its characteristics. Gravity field of earth and Isostasy. Geomagnetism, elements of earth's magnetism: Internal, External fields and their causes, Paleomagnetism, Polar wandering paths, Seafloor spreading, geophysical evidences. Elastic waves, internal structure of earth, variation of physical properties in the interior of earth.
Books - Fundamentals of Geophysics by William lowrie (Chapter 1 and 2 mainly)
- Introduction to geophysics (
download)
b.Earthquake and Engineering Seismology:
Syllabus: Seismology, earthquakes, focal depth, epicenter, great Indian earthquakes, Intensity and Magnitude scales, Energy of earthquakes, foreshocks, aftershocks, Elastic rebound theory, Fault plane solutions, Seismicity and Seismotectonics of India, Frequency-Magnitude relation (b values), Velocity structure, VpNs studies. Elastic waves, their propagation characteristics. Seismic ray theory for spherically and horizontally stratified earth, basic principles of Seismic Tomography and receiver function analysis, Seismic network and arrays, telemetry systems, Earthquake prediction; dilatancy theory, short-term, middle-term and long- term predictions, Seismic microzonation studies, application for engineering problems, Seismometry, Principle of electromagnetic seismograph, displacement meters, velocity meter, accelerometer, WWSSN stations, Strong motion seismograph, seismic arrays for detection of nuclear explosions, Broadband seismometry.
Books - Fundamentals of Geophysics by William lowrie (Chapter 3)
- Microearthquake Seismology and Seismotectonics of South Asia by J.R. Kayal (only do those topics from this book which are not covered in William Lowrie)
Earthquake Prediction PDF (
download)
Dilatancy Diffusion Model (
download)
c.Mathematical methods in Geophysics:
Syllabus: Properties of scalars, vectors and tensors, Elements of vector analysis, Gradient, Divergence and Curl, Gauss's divergence theorem, Stokes theorem, Definition of fields, Gravitational field, Newton's Law of gravitation, Gravitation potential and fields due to bodies of different geometric shapes, Electrostatic field, Coulomb's law, Electrical permittivity and dielectric constant, Basic guiding equations, Magneto static field, Origin of Magnetic field, Ampere's law, Biot and Savart's law, Geomagnetic fields, Magnetic fields due to different type of structures, Solution of Laplace equation in Cartesian Coordinate, Cylindrical Polar Coordinate and Spherical Polar Coordinate, Complex Variables in Potential theory, Green's theorem in Potential Theory. Concept of Image in Potential Theory, Analytical continuation in Potential fields, Numerical Methods in Potential Theory. Electrical fields in geophysics, point source, continuous distribution and double layers, equipotential and line of force. Current and potential in the earth, basic concept and equations of electromagnetic, Maxwell's equations, boundary conditions, elliptic polarization, electromagnetic potential and waves, radiation from dipoles, retarded potential, near and far fields, radiation resistance, EM field of a loops of wire on half space, multi-layered media, impedance and its application.
Note - I suggest you only do the blue colored portion and leave the rest as some of the topics will be repeated further in Part B of your syllabus and some are meant to be left.
Book -Mathematical Physics by H.K Dass
Notes for solution of laplace' equation in different coordinate system(
download)
d.Geophysical Inversion:
Syllabus: Fundamental concepts of inverse theory, Basic definition of inversions with application to Geophysics. Probability, Inverses with discrete and continuous models. Forward problems versus Inverse problems. Formulation of inverse problems and their relation to a matrix problem, linear inverse problems, classification of inverse problems, least square solutions and minimum norm solution, concept of norms, concept of 'a priori' information, constrained linear least square inversion, review of matrix theory. Introduction to finite difference method, forward, backward and central difference method. Application of finite difference method for solving Helmholtz equation. Introduction to finite element method, various steps, simple examples showing application of finite element method. Models and data spaces, householder transformation, data resolution matrix, model resolution matrix, Eigen values and Eigen vectors, singular value decomposition (SVD), generalized inverses, Non-linear inverse problems, Gauss Newton method, steepest descent (gradient) method, Marquardt-Levenberg method, Earthquake location problem, tomography problem. Probabilistic approach of inverse problems, maximum likelihood and stochastic inverse methods, Backus-Gilbert method, Global optimization techniques, genetic algorithm, simulated annealing methods, examples of inverting geophysical data.
Book - Geophysical Data Analysis: Discrete Inverse Theory By William Menke
- Many topics are not in this book or not covered well enough were done from various internet sources. I suggest that if u have studied
Geophysical Inversion as a subject in college ....go for the class notes.
Notes on few topics (
download)
Geophysics Paper-II Part-A:
Geophysical Potential Fields (Gravity and Magnetic):
Syllabus: Geophysical potential fields, Inverse square law of field, Principles of Gravity and Magnetic methods, Geoid, Spheroid, Nature of gravity and its variation, Properties of Newtonian potential, Laplace's and Poisons equations, Green's theorem, Gauss law, Concept of Bouguer gravity anomaly, Rock densities, factors controlling rock densities, determination of density, theory of isostasy, Earth's main magnetic field, origin, temporal variations, Geomagnetic elements, Coulumb's law of magnetic force and fields, intensity of magnetization and induction, magnetic potential and its relation to field, units of measurement, origin of magnetic anomalies, interrelationship between different components of anomalies, Poison's relation, Magnetic susceptibility, factors controlling susceptibility (Bulk chemistry, cooling history, metamorphism..), magnetic minerals, rock classification, Natural and remnant magnetism, Asiatic and Spinner magnetometers, demagnetization effects. Principles of Gravity and Magnetic instruments, Plan of conducting GM surveys, reduction of gravity and magnetic data, Airborne magnetic surveys and magnetic gradient surveys, Shipborne surveys, Gravity and Magnetic data reduction, IGSN Gravity bases, International Gravity formula, IGRF corrections for magnetic field. Separation of regional and residual anomalies, ambiguity in interpretation, Application of GM surveys for Geodynamic studies, Mineral Exploration, Environmental studies.Data processing and interpretation of anomalies, modeling of anomalies.
Books - William Lowrie (Chapter 2 and 5)
- Applied Geophysics By Telford
-An Introduction to Geophysical Exploration by Philip Kearey
b. Electrical and Electromagnetic methods:
Syllabus: Electrical properties of rocks and their measurement, concepts and assumptions of horizontally stratified earth, anisotropy and its effects on electrical fields, the geoelectric section and geological section. Resistivity method, fundamental laws, concept on natural electric field, electrode configuration, choice of methods, Profiling, Vertical Electrical Sounding.SP Method, Origin of SP, application of SP surveys, Origin of Induced Polarization, Membrane and Electrode potential, time and frequency domains of measurement, IP, chargeability, percent frequency effect and metal factor, dipole theory of IP, Application of IP surveys for mineral exploration (disseminated sulphides). Electromagnetic methods/ Telluric/Magneto Telluric methods, Passive and Active source methods, Maxwell's equations, electromagnetic potential and wave equations, boundary conditions, long wave length approximation, depth of penetration, amplitude and phase relations, real and imaginary components, Principles of EM prospecting, various EM methods, Dip angle method, Turam method, moving source-receiver methods-horizontal loop (Slingram) method, AFMAG, and VLF methods, Airborne EM systems - rotary field method, INPUT method, EM Profiling and sounding, Interpretation of EM anomalies, Principles of Ground Penetrating Radar (GPR), Origin and characteristics of MT fields, Instrumentation, Field methods and interpretation of MT data and applications.
Book - Main Book for this topic is Telford, Some parts are also to be read from Lowrie (Chapter 4).
-For Magnetotelluric follow 'Practical Magnetotellurics' by Simpson and Bahr (stick to the syllabus).
MT Processing PPT (
download)
c. Seismic Prospecting:
Syllabus: Basic principles of seismic methods, Fermat's principle, Snell's law, Reflection, refraction and diffraction from multilayered medium, Reflection and transmission coefficients, propagation model for exploration seismology, Seismic resolution, Seismic absorption and anisotropy, Seismic data acquisition, sources of energy, Geophones, geometry of arrays, Instrumentation, digital recording Seismic Surveys: Principle for multilayer refraction Travel time curves, corrections, Interpretation of data, Reflection principles, CDP, data processing, corrections, NMO correction, Interpretation of data, Fundamental of VSP method, Seismic Tomography. Principles of High Resolution Seismic (HRS) for coal exploration.
Books - A HANDBOOK FOR SEISMIC DATA ACQUISITION IN EXPLORATION By Brian J. Evans (
download) (for acquisition part)
- 'Tomography' I did not prepared but is given in William Lowrie.
- Read 'HRS' from Internet.
-From Basic Principles ...........coefficients - given in William Lowrie.
- VSP notes (
download) (these notes are enough for this topic)
- For Processing and Interpretation - go for the class notes . If not, can be done from Dobrin (
download)
- Dobrin includes Processing and Interpretation part for every geophysical exploration method. You can refer it for the same.
d.Borehole Geophysics (Principles of Well logging):
Syllabus:
Objectives of well logging, fundamental concepts in borehole geophysics, borehole conditions, properties of reservoir rock formations, formation parameters and their relationships-formation factor, porosity, permeability, formation water resistivity, water saturation, irreducible water saturation, hydrocarbon saturation, residual hydrocarbon saturation; Arhcie's and Humble's equations; principles, instrumentations, operational procedures and interpretations of various geophysical logs, SP log, resistivity and micro resistivity logs, nuclear/radioactive logs, acoustic impedance and propagation logs, temperature log, caliper log and directional logs; production logging; clean sand and shaly sand interpretations; overlay and cross-plots of well-log data, determination of formation lithology, sub-surface correlation and mapping, delineation of fractures; application of well-logging in hydrocarbon, groundwater, coal, metallic and non-metallic mineral exploration.
Book - Petrophysics by Paul Glover (
download)
- I did not prepared Formation evaluation (
Red portion above)
GEOPHYSICS - PAPER III PART-A:
a.Radiometric Exploration / Airborne Geophysical surveys for Geological Mapping:
Syllabus: Principles of radioactivity, radioactivity decay processes, units, radioactivity of rocks and minerals, Instruments, Ionisation chamber, G-M counter, Scintillation meter, Gamma ray spectrometer, Radiometric prospecting for mineral exploration (Direct/Indirect applications), Radiometric prospecting for beach placers, titanium, zirconium and rare-earths, portable gamma ray spectrometry and radon studies in seismology, environmental Applications, logging methods, radiometric dating techniques. Airborne geophysical surveys, planning of surveys, sensors, data corrections, flight path recovery methods, applications in geological mapping, interpretation of maps, identification of structural features, altered zones.
Books - Lowrie (chapter 4)
- Telford (chapter 10)
-For all airborne methods (magnetic, EM, radioactive and gravity) refer this paper (
download)
b.Marine Geophysics:
Syllabus: Oceans and Seas, origin of continents and oceans, salinity, temperature and density of sea water. Introduction to Sea-floor features: Physiography, divisions of sea floor, continental shelves, slopes, aprons and abyssal planes, growth and decline of ocean basins, turbidity currents, submarine sedimentation and stratigraphy, occurrence of mineral deposits and hydrocarbons in offshore. Geophysical surveys and instrumentation, Gravity and Magnetic surveys, Instrumentation used in ship borne surveys, towing cable and fish, data collection and survey procedures, corrections and interpretation of data. Oceanic magnetic anomalies, sea floor spreading, Vine-Mathews hypothesis, geomagnetic time scale and dating sea floor, linear magnetic anomalies, Oceanic heat flow, ocean ridges, basins, marginal basins, rift valleys. Seismic surveys, energy sources, Finger, Boomer, Sparker, Exploder, Air gun, Vapour cook, Hydrophones, processing, data reduction and interpretation. Bathymetry, echo sounding, bathymetric charts, sea bed mapping, seabed sampling, dredging and coring, Navigation methods and Position location methods.
Note - It is a combination of Lowrie, telford, evans and some other topics. Did not prepared dedicatedly. So, only the topics I was able to find in these books I prepared and left out the rest.
c. Geophysical Signal Processing:
Syllabus: Various types of signals, sampling theorem, aliasing effect, Fourier series and periodic waveforms, Fourier transform and its properties, Discrete Fourier transform and FFT, Auto and cross correlations, Power spectrum, Delta function, unit step function. Time domain windows, Z transform and properties, Inverse Z transform. Principles of digital filters, types of filters, moving average and recursive and non recursive filters Amplitude and phase response filters low pass, band pass and high pass filters, Processing of Random signals. Signal enhancement for gravity and magnetic maps; regional residual separation, continuations, evaluation of derivatives, pseudo gravity transformations, reduction to poles and equator, Improvement of signal to noise ratio, source and geophone arrays as spatial filters. Earth as low pass filter.
- Any standard signal processing book will do the job.
- From 'regional residual separation...........Earth as a low pass filter' can be found in telford, dobrin, lowrie.
- Regional Residual Separation - Page 84 William Lowrie (2.6.1 and 2.6.2) , Page 26 Telford
- Upward and downward continuation - Page 144, Topic 6.11, from Kearey and Brooks ( It is a method to separate regional and residual) . Also, given in Telford (Page 32, 2.6.7) but I got a better understanding of it from Kearey.
- evaluation of derivatives - I think this topic basically talks about the second derivative method. It is given in Telford (Page 32, 2.6.5)
- Pseudo gravity transformations - Read from this (
download)
- Reduction to pole and equator - For this topic try these research papers. (
roy) (
aina) (
Jain) . Do not go deep into the mathematics, just try to answer the following questions:
- What is Reduction to pole and equator?
- How it is done?
- Why it is done? (In which case we prefer reduction to pole over reduction to equator and vice-versa).
- Improvement in signal to noise ratio - This is done during both acquisition and processing (sometimes in interpretation). Prepare an answer in accordance with that.
- Earth as a low pass filter - Lowrie (Page 135-136)
d.Remote Sensing and GIS applications:
Syllabus:
Fundamental concepts of remote sensing, electromagnetic radiation spectrum, energy-frequency-wavelength relationship, Boltzman Law, Wien Law, electromagnetic energy and its interactions in the atmosphere and with terrain features; elements of photographic systems, reflectance and emittance, false color composites, remote sensing platforms, flight planning, geosynchronous and sun synchronous orbits, sensors, resolution, parallax and vertical exaggeration, relief displacement, mosaic, aerial photo interpretation and geological application. Fundamentals of photogrammetry, satellite remote sensing, multi-spectral scanners, thermal scanners, microwave remote sensing, fundamental of image processing and interpretation for geological applications. Introduction to Geographic Information Systems (GIS) spatial data structures, visualization and querying, spatial data analysis.
Books - Fundamentals of Remote Sensing by George Joseph
-Remote Sensing and GIS by Basudeb Bhatta
- Remote Sensing for Earth Resources by D.P. Rao
