GEOL 492/692 - Applied Geophysics

GEOL 492/692
Applied Geophysics

offered each Spring semester
Instructor: John Louie, 217 LME, 784-4219, louie@seismo.unr.edu

Attendance at the class Field Exercise is required, for the entire Spring Break period. Exceptions can only be made in cases of illness, disability, conflicting religious observance, or similarly serious situations.
I encourage any student needing to request accommodations for a specific disability to please meet with me at your earliest convenience to ensure timely and appropriate accommodations.
Alumni of Geol 492/692 may participate in the Spring Break Field Exercise to receive one credit.

Learning Objectives: This course is a survey of geophysical techniques applied to solving geoscience and engineering problems in resource exploration and development, natural hazards, and pollution control. The course is intended to be a practical, hands-on, field-oriented course on the applications of geophysics to these problems. For each topic, the development will proceed from basic principles (theory) through methodology and applications, to case histories. Applications will be emphasized; theory will be kept to essentials. The basic principles and operational procedures of each method will be presented, along with discussions of where the method is and is not applicable. Case histories will be included to illustrate applications. Assigned readings and composition of literature reviews will be an integral part of the course work.

The course has 4 elements: lectures, lab exercises, reading case-history literature, and a field project.
The description below is available to WWW browsers at the URL http://www.seismo.unr.edu/ftp/pub/louie/class/492-syll.html.

Lectures

In general two 75-minute lectures will be given each week, focusing on processes, concepts, and methods reported in the literature. Notes will be available for copying in advance of each lecture. The required text is W. Telford, L. Geldart, and R. Sherriff, Applied Geophysics, Cambridge Univ. Press, ISBN 0521339383 . The schedule of readings from the text are noted in the syllabus below.

Lab Exercises

About seven laboratory exercises or problem sets will be assigned, to test students' grasp of key concepts and methods. All of these exercises will be computer-based, with software provided by the instructor for download from this web page. One exercise requires use of one of the PC, Mac, or Sun computers within the Seismological Lab, to access licensed commercial software. Links are given from the assignments in the syllabus below. However, students are responsible for finding the computer resources needed to complete the exercises on their own time. All exercises will be Windows-compatible and most will be MacOS 8.1 and Linux or Solaris compatible as well.

Please inform the instructor immediately if you cannot locate a suitable computer, or if you feel a class lab session needs to be scheduled for the exercise. In general each lab exercise will be due one week after the lecture covering the included concepts. Students may work together to complete the exercises, but all must turn in only their own work. Late exercises will be accepted with a 10% penalty for a week or two after the due date, possibly later at the instructor's discretion.

Reading Case-History Literature

Students will write about six abstracts of scientific articles on case histories. Lists of published case histories to select from are linked in the syllabus below. Everyone should turn in an original abstract of any one or more of the assigned readings. More than one student may write an abstract on the same reference, but students must write their abstracts on their own. The abstract should be between 100 words and 1 page long. It will be evaluated for neatness, English usage, and how well it ``concentrates the essential information'' of the chosen reference(s). Please refer to the handout on Pointers for writing good abstracts.

Field Project

The class will conduct a small-scale geophysical field investigation in Nevada or eastern California during the March 26 - April 3 Spring Break, or six Saturdays in March and April (all of them). Seismic, gravity, magnetic, and electrical methods will be employed, and interpreted. Planning and mobilizing for each geophysical method will be assigned to a student or group from the class. Additional details will be announced in February. There is a field project preparation web page from 2003 that will be updated with this class's objectives.

Each method's group will present their analysis with a 15-minute seminar on May 5. While the class will collectively analyze the data obtained, students will be responsible for their own written reports. Each should describe the objectives, previous work, methods, results, and implications of the entire project in 5 to 10 pages of text, plus figures. The class may be able to publish its collected results. There will be no final exam, unless the field project becomes a complete failure.

Grades will be calculated as follows:

Lab Exercises		40%	Abstracts	30%
Oral Presentation	 5%	Field Report	25%

Syllabus and Schedule

1/19	Seismic principles - moduli, wave propagation, Snell, reflection, surface waves Text: p. 136-143, 147-162
1/24	Seismic principles - porosity, Q, sources, geophones and digital recorders Text: p. 192-207 A wave-modeling facility, with links to movies
1/26	Refraction - acquisition, sources, t-x plots, depth, dip, reversal Text: p. 162-176, 209-216
1/31	Refraction - low-vel & thin hidden layers, v-z ambiguity, surface wave applications (media files) - Abstract due on engineering seismic case history Text: p. 235-243
2/2	Reflection principles - profiling, sounding, NMO, dip - Refraction lab 2 demo Text: p. 176-186
2/7	Reflection principles - Vrms, Dix, vert resolution, horiz resolution Text: p. 207-209
2/9	Reflection acquisition - spreads, s/n, stack chart, phases, spatial aliasing - First-arrival picking and velocity inversion lab due Text: p. 186-192
2/14	Field project objectives - geologic setting, previous geophysics, planning Briggs's presentation
2/16	Reflection analysis - displays, spectra, BP filtering, gather slicing - Surface-wave dispersion analysis and modeling lab due Text: p. 216-228
2/21	NO CLASS - Presidents Day Holiday
2/23	Reflection analysis - CMP stacking, CV stack picking, diffractions, migration Text: p. 229-233, 243-248
2/28	Hydrocarbon exploration - struct & stratigr traps, well logs, seismic stratigraphy - Abstract due on seismic reflection case history Text: p. 233-235, 248-272
3/2	Gravity principles - densities, corrections, instruments, acquisition Text: p. 6-7, 10-26
3/7	Gravity interpretation - modeling, trends, contouring, spatial filters - Reflection Processing Lab due Text: p. 26-48
3/9	Magnetics principles - properties, susceptibility units, diurnal drift, storms, instruments, acquisition Text: p. 62-63, 67-84
3/12-3/13	*Class Field Weekend*
3/14	Magnetics interpretation - modeling, trends, contouring, poles, filters Text: p. 84-114
3/16	Gravity/magnetics case studies - basin and bedrock geometry - Gravity Lab (due 3/18 4 PM) - Talwani inversion Text: p. 48-52, 114-134
3/19-3/20	*Class Field Weekend*
3/21	GPS and Geodesy principles (1 Mb PDF)
3/23	GPS acquisition and analysis, radar interferometry - Magnetics Lab due - GM-SYS on DOS
3/26-4/3	Spring Break - 2005 Field Photo Album - Previous Fieldwork Photo Albums: 2000; 2002; 2003
4/4	Field interpretation - elements of professional report, integration
4/6	GPS applications and case histories
4/11	Electrical/hydraulic properties - rocks, fluids - Abstract due on potential fields case history
4/13	DC Resistivity - acquisition, apparent resistivity, modeling, curve fitting
4/16-4/17	*Class Field Weekend*
4/18	Frequency-domain electromagnetics - wavelengths, phase, skin depth - Abstract due on geodetic/inSAR case history
4/20	Time-domain electromagnetics - dynamos, eddy currents, acquisition, modeling
4/23-4/24	Possible Backup Class Field Weekend
4/25	Induced polarization, self potential - theory, acquisition, interpretation - Resistivity modeling lab due - uses RESIX demo software on DOS
4/27	NO CLASS - Seismological Society Meeting hosted by UNR at Lake Tahoe
5/2	Electromagnetic case studies - deep-crustal fluids, waste plume characterization - Abstract due on electromagnetic case history
if time permits	The borehole environment - drilling, casing, fluids, filtrates & cakes
if time permits	Borehole methods - SP, induction, laterologs, acoustic, gamma, neutron
Friday 5/6	Group Project Results Presentations during final period LMR 355 4:30-6:30 PM - Abstract due on borehole case history (if assigned)
Weds. 5/11	Individual Project Reports Due 5:00 PM LME 217