Undergraduate Course: Fields and Waves (EASC09033)
|School||School of Geosciences
||College||College of Science and Engineering
|Credit level (Normal year taken)||SCQF Level 9 (Year 3 Undergraduate)
||Availability||Available to all students
|Summary||The course introduces a common framework to address diverse problems of Earth physics based on special cases of the telegraph equation.
The course describes the geophysical applications to acoustic wave propagation and to gravity, magnetic, electrical, electromagnetic, heat flow, and seismic problems.
This course extends the Teaching of U00545 Physics 2A: Forces, Fields and Potentials to general features of waves, fields, and diffusive propagation in continuous media. The course also extends the teaching of electricity and magnetism in Physics 2A to geophysical problems including current flow in the Earth and variations of conductivity within it.
Lastly, the course introduces the concepts of passive and active measurement of geophysical data and discusses the sources required for active geophysical exploration.
The apportioning of topics between lectures is approximately as follows.
Derivation of the Telegraph Equation.
Total time derivative and partial time derivative; acceleration of a particle; linearization; equation of continuity; pressure waves in a fluid; constitutive equation; 1-D, 2-D and 3-D acoustic wave equations; solution to the 1-D wave equation.
Newton's law of gravitation; gravity; gravitational potential; Laplace's equation; Poisson's equation; force due to electric charge and magnetic poles.
Components of strain and stress; equations of motion in an elastic medium; Hooke's law of elasticity; elastic wave equations, P-waves and S-waves; particle motion of a plane wave; solutions to the wave equation; normal modes: oscillations of a string.
Electromagnetic (EM) Waves and Heat Flow
Maxwell's equations; constitutive relations; EM wave equations; plane wave solutions of the EM wave equations, skin depth, wavelength; EM propagation in air and free space; EM propagation in conducting media; diffusion equation. Heat flow in solids.
Revision of Fourier Theory
Fourier transform; the delta-function; resolution and bandwidth; similarity theorem; impulse function; impulse response; linear filters and convolution; convolution theorem; derivative theorem; wavefield transformation.
Passive Geophysical Measurements
Gravity anomalies; gravity meters, measurements and corrections; gravity gradiometry and gravity measurement on a moving vessel or aeroplane; non-uniqeness of gravity interpretation; magnetics; heat flow; the magnetotellurics method; classical seismology; Adams-Williamson equation.
Active Geophysical Measurements
Controlled Source Electromagnetics (CSEM) and the role of fluids; conventional CSEM; transient CSEM and MTEM; seismic exploration and data acquisition; seismic exploration and reflection coefficients for acoustic waves; seismic exploration and normal moveout correction and stacking.
Seismic Sources and Receivers
Monopole source - dynamite on land; the Vibroseis method and vibrator force source; Vibroseis method and correlation with the sweep; Vibroseis method and generation of the sweep; Vibroseis method and the downgoing wavefield; marine airgun source; marine airgun source and spectrum and effect of sea surface; marine airgun source and arrays of air guns; effect of sea-surface reflection at receiver; geophones, hydrophones and accelerometers.
Manipulation of Wavefield Measurements
Sampling theorem and aliasing; sources of noise; filtering; deconvolution; upward and downward continuation.
Information for Visiting Students
|High Demand Course?
Course Delivery Information
|Not being delivered|
On completion of this course, the student will be able to:
- Familiarity with essential mathematical techniques.
- Familiarity with concepts of classical physics applied to Earth problems.
- Confidence in the conceptual framework of analysing fields and waves.
- Appreciation of the application of physical and mathematical techniques to diverse Earth problems.
- Appreciation of manipulation of geophysical data to obtain physical properties of the Earth.
|"Fundamentals of Geophysics" by William Lowrie, Cambridge University Press.|
"A Student's Guide to Geophysical Equations" by William Lowrie, Cambridge University Press.
Course notes are also provided online.
|Graduate Attributes and Skills
|Additional Class Delivery Information
||Thursdays at 11:10-13:00, Weeks 1-11
|Course organiser||Prof Anton Ziolkowski
Tel: (0131 6)50 8511
|Course secretary||Ms Casey Hollway
Tel: (0131 6)50 8510