USU GEO 5660/6660: Applied Geophysics

GEO 5660/6660: Applied Geophysics

Syllabus & Pre-requisites

SYLLABUS (PDF)

Recommended Text (& Errata):
Introduction to Applied Geophysics: Exploring the Shallow Subsurface (Amazon.com)
ERRATA: Introduction to Applied Geophysics, Burger et al. 2006

Program, Course, & Pre-requisites:
USU Program: Geology - BA, BS
Catalog: GEO 5660/6660 - Applied Geophysics
Applied Geophysics - 2018 Course Pages (Tony Lowry)

Finals Schedule (Course Catalog)

Field Trips: Dry Canyon, on Tuesdays, March 31, April 7 & 14 *** CANCELED AS PART OF COVID-19 MEASURES ***

Homework/Lab Assignments & Quizzes

    
HW #1:        [SOLUTIONS]
Due: Tuesday, January 28th, 3 PM
    
LAB #1: See Lecture5 & associated links
    
LAB #2: Tue, Jan, 28: Seismic Refraction; Introduction to textbook software, REFRACT & REFLECT.      (Lab Assignment)
Due: Tuesday, February 4, 3:00 PM
    
LAB #3: Tue, Feb, 25: Seismic Refraction Analysis: QUAD Data & Gosport, IN      (Lab Review)      (Quad Data, collected Feb 18, 2020.)
Due: Wednesday, March 11, 5:00 PM
    
LAB #4: Tue, Mar, 10: Seismic Reflection Analysis: QUAD Data      (Lab Review)      (Quad Data, collected Feb 18, 2020.)
Due: Wednesday, March 18, 5:00 PM
    
LAB #3/#4 - REDO PARTS: Mon, Mar, 23: Seismic Refraction/Reflection      (Lab 3, Q.4 Hints)      (Lab 4, Q.3 & Q.4 Hints )
Due: Wednesday, April 1, 5:00 PM
    
LAB #5: Sat, April 04: Gravity Modeling of Little Mountain, Idaho      (Lab Review)      (Gravity Data)
Due: Monday, April 12, 5:00 PM
    

    
QUIZ #1: Topics - Up to and including Lecture 10.
Tuesday, January 28th, 3-3:30 PM
    
QUIZ #2: Topics - Up to and including Lecture 22.
Tuesday, March 10th, 3-4 PM
    
QUIZ #3: Topics - Potential Field Methods: Up to and including Modules covered until Friday, April 17th.
Monday, March 20th, *** 1-1.5 hour OPEN-BOOK/-NOTES exam, DUE 5 PM (to Rob) ***
    
FINAL
Monday, March 27th, *** 2.5-3 hour OPEN-BOOK/-NOTES exam, DUE 6 PM (to Ravi) ***
    

Lectures/Notes

Terminology/Notation cheat-sheet (thanks to Rob McDermott!)

Lecture 1: Introduction. Seismic Waves - reflection, refraction, diffraction; Travel-time curves; Tomography

Lecture 2: Scope of Geophysics; Careers in Geophysics; Geophysical Imaging - Focus of this course;
Wave reflection - Huygens' & Fermat's Principles.

Lecture 3: Huygens' & Fermat's Principles Revisited; Reflection of a Wavefront; Refraction of a Wavefront;
Snell's Law; P- & S-wave velocities & angles.
Lecture 4: Introduction to the wave equation (Derivation of 1D, Cartesian version) - general solutions, wave velocity

Lecture 5/Lab 1: 1D-Cartesian wave equation & characteristic solutions revisited; Wave energy in terms of Amplitude & Frequency;
1D-Spherical wave equation - 1/r reduction in amplitude and 1/r2 reduction in radiated energy.
LAB: Snell's Law applied to incident P-/S-waves; Spread-sheet calculations to reproduce Fig 2.15(b)-(e) & Table 2.3 of Text.
Lecture 6: 1D-Cartesian wave equation - Wave energy revisited; Review of Snell's Law & Critical Refraction
Seismometer - introduction.
Lecture 7: Seismometry - Introduction to simple & damped harmonic oscillators;

Lecture 8: Seismometry - Simple vs. damped harmonic oscillators (mechanical & electrical); Fundamental frequency, and effects of damping
Critical-/Over-/Under-damped systems; Convolution Basics;
LAB: Simple harmonic & damped solutions - spread-sheet calculations for developing intuition.
Lecture 9: Seismic wave amplitudes, energy density, & flux; Scattered waves - Zoeppritz Equations;
Calculating reflection & transmission amplitude coefficients ( CREWES - U. Alberta); Also see Tooley et. al 1965

Lecture 10: Seismic signals - time vs. frequency domain; Brief overview of Fourier Transforms, convolution, & discrete sampling.

Lecture 11: Seismometry wrap-up: Seismometer response & calibration; Signal-to-noise Ratio (Db) & dynamic range;
Seismic instrument filters; How convolution works (example using two 1D arrays). [Slides courtesy of Hiner Igel, U. Muenchen]

Lecture 12: Refraction seismology, khorizontal layers, for k = 2, 3, ...., N.
Lecture 13: Refraction seismology, kDipping layers, for k = 2,...., N.

Lecture 14: Refraction seismology - Similarities between horizointal & dipping layer equations; Hidden layer problem;
t-x plot discontinuities due to vertical offsets.

Lecture 15: Refraction seismology - Summary of all equations; Vertical offset time difference; Time-delay derivation from path geometry;
"Plus-Minus" Method

Lecture 16: Refraction seismology - understanding the Plus-minus method; Field considerations
Lecture 17: Reflection seismology - Single horizontal layer; Normal Moveout; Multiple horizontal layers

Lecture 18: Reflection seismology - Green's Method; Dix equations; Applications
Lecture 19: Reflection - Dipping reflector
Lecture 20: Reflection - Dipping reflector; TDMO; Practical Considerations
Lecture 21: Reflection seismology - Horizontal & Vertical resolution; data samplling; Practical computer data processing steps:
I. Static correction; II. TNMO correction & velocity analyses; III. Common Depth Point (CDP) stacking; IV. Migration;
Other adjustments - amplitude, transmission, and filtering [Based on Tony's lectures between Feb 9-12, 2018]

Lecture 22: Industry seismic data processing: 2D/3D/4D high-resolution processing
[Based on Tony's lectures between Feb 14-20, 2018]

Lecture 23: Ground Penetrating Radar: an overview
[Based on Tony's lectures between Feb 21-23, 2018]

Lecture 24: Review of Seismic Refraction & Reflection

Modules: Post COVID19 Measures: Potential Field Methods & Well Logging

Video lecture for each module below is posted to the Canvas Course Page. Please email me with any feedback!

Gravity Module 1-1: Introduction to Potential Field Methods, Gravity, and Gravity Anomalies

Gravity Module 1-2: Gravity Anomalies & Gravity Measurement Principles

Gravity Module 2-1: Gravity Corrections & Estimating the residual gravity signal due to interior density anomalies

Gravity Module 2-2: Gravity Anomalies due to some standard shapes of interior density anomalies

ElectroMagnetism: Magnetics Module 1-1: Fundamentals: How does magnetism work? External and Induced Magnetic Fields; Magnetic materials

ElectroMagnetism: Magnetics Module 1-2: Fundamentals: Earth's Magnetic Field - Core & Crustal Fields; Measurement of field strength;

ElectroMagnetism: Magnetics Module 1-3: Magnetic Anomalies due to Magnetized crustal bodies: Theory, Data Reduction, & Calculation

ElectroMagnetism: Magneto-Tellurics: Telluric Currents and the MT Method; MT Inversion Results: Resistivity structure of the Crust & Upper Mantle

ElectroMagnetism: DC-Resistivity Module 1: DC Resistivity - Fundamentals & Theory; Estimation of apparent resistivity of 1-2-3-layered halfspace

ElectroMagnetism: DC-Resistivity Module 2: DC Resistivity - Profiling vs. Sounding; Pseudosections; Local Examples & other applications

Well-/Wireline logging: Modified/Condensed from Tony's lectures (2018: April 16 & 20)