Learning Outcomes
1) Understanding the basic principles of Gravity and Magnetic Methods of Geophysical Prospecting.
2) Rough design of a gravity or magnetic survey in relation to the expected subsurface structure.
3) Comprehension of the importance of measuring step in optimizing the scientific result with respect to available means.
4) Understanding the necessity of the reductions applied to gravity and magnetic readings.
5) Understanding the relation of Bouguer anomaly with the density variation at the upper layers of the Earth’s Crust.
6) The student will be able to “read” and qualitatively assess the Bouguer maps.
7) Understanding the relation between magnetic total field anomalies and variations of magnetization at the upper layers of the Earth’s Crust.
8) Understanding the necessity of aeromagnetic surveying at not easily accessible areas.
9) Understanding the way an aeromagnetic survey is carried out.
10) After the successful completion of the course the student will be able to read and qualitatively interpret ground and airborne magnetic maps.
11) Understanding the difference between induced and remanent magnetization.
12) After the successful completion of the course the students will be able to assess if a gravity and/or magnetic survey is needed and what it can be obtained for the solution of geological, geotechnical or archaeological problems.
13) After the successful completion of the course the students will be able to employ gravity and/or magnetic maps for the solution of geological, geotechnical or archaeological problems.
Course Content (Syllabus)
The Earth's gravity field, General formulae of the gravity field, Newton’s law, gravitational prospecting methods, density if rocks and minerals, measured quantities, measuring instruments, gravity surveying and removal of drift and tidal effects, reductions of gravity measurements and production of Free Air and Bouguer anomalies, regional residual separation, estimations of the density of the near surface layers, processing and interpretation methods.
Megnetic method of geophysical prospecting, measured quantities, magnetic susceptibility of rocks and minerals, instruments for magnetic surveying, measuring techniques for the total magnetic field and its spatial derivatives, airborne measurements.
Examples from mineral and hydrocarbon exploration, applications in studying the subsurface geological and tectonic setting, applications in Archaeology and environmental studies.
Course Bibliography (Eudoxus)
Παπαζάχος, Β.Κ. Εισαγωγή στη Εφαρμοσμένη Γεωφυσική. Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης, Θεσσαλονίκη, 1986..
Τσόκας, Γ.Ν., Γεωφυσική διασκόπηση με τις μεθόδους των δυναμικών πεδίων, Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης, Θεσσαλονίκη, 1999.
Additional bibliography for study
Blakeley, R.J. Potential theory in gravity and magnetic applications. Cambridge University Press, New York, 1995.
Boyd, J. Lecture notes on Potential Field methods. Colorado School of Mines, INTERNET address http:/www.mines.edu, 1997.
Chapin, D.A. The theory of the Bouguer anomaly: a tutorial. The Leading Edge, 15, 5, 361-363, 1996.
Dobrin, M.B. and Savit, C.H. Introduction to geophysical prospecting. McGraw-Hill Book Company, New York , 1988.
Garland, G.D. The Earth’s shape and gravity. Pergamon press, Oxford,1977.
Parasnis, D.S. Principles of Applied Geophysics, Chapman and Hall, London, Fifth Edition, 1997.
Sheriff, R.E. Encyclopedic dictionary of Exploration Geophysics, Society of Exploration Geophysicists, Tulsa, 1981.
Telford, W.M., Geldart L.P. and Sheriff, R.E. Applied Geophysics, Cambridge University press, New York, 1993.
Tsokas, G.N. and Hansen, R.O. Study of the crustal thickness and the subducting lithosphere in Greece from gravity data. Journal of Geophys. Research, 102, 20585-20597, 1997.