W. Steven Holbrook

GEOL 5180: Reflection Seismology

 

Fall 2011, 3 units

 

Meeting Times: MWF 9-9:50 am, ESB 1004

 

Instructor:            Prof. W. Steven Holbrook            Office:    ESB 3016

                                    Office Hours:              M 2-3 pm, W 11-noon,

                                                                        Th 10-11 am, or by appt.

                                    Phone:              766-2427

                                    Email:              steveh@uwyo.edu

 

Course description:

             In this course you will learn the basics of reflection seismology. By the end of the semester, you should understand basic wave propagation, rock physics, and key aspects of seismic data acquisition, processing, display, and interpretation, including 3D seismic data interpretation.  Although the relevant background theory will be introduced, the emphasis will be on gaining practical knowledge of using and interpreting seismic reflection images. 

            One of the goals of this class is to give you a basic computer-based skill set for analysis of seismic data.  For that reason, we’ll spend some time learning Matlab, which is a widely used (and relatively inexpensive) data analysis package (which can also be easily adapted to analyze seismic data).

            As part of the course, you’ll work on several “case studies”, in which you’ll display and interpret marine seismic reflection data sets from my research group.  The case studies will be the principal way you’ll gain hands-on experience in working with seismic data (not just paper plots of seismic data).

            In the last case study, you’ll do an interpretation of an industry 3D seismic data set.  This exercise will familiarize you with modern, computer-based 3D interpretation, from tracking horizons and calculating isopachs, to calculating and displaying attribute sections in three dimensions.

            The final project will be a 5-page written paper on any topic of reflection seismology.  You can investigate a hot new topic in data processing or analysis (e.g., AVA analysis), summarize knowledge gained from reflection seismology about a particular environment or topic (e.g., “seismic oceanography”), or develop a research paper of your own.  The topic should be agreed upon in advance by the instructor, so I’ll be happy to consult and brainstorm with you on possible topics.

 

Course Website: 

            I will maintain a course website, containing course information, lecture files, homework assignments, etc.  You can find the website here:

http://steveholbrook.com/geol_5180/

 Much of the material on the website is password-protected; you will receive the login and password in class.

Computers and Software:

            There are many software packages for processing seismic data – from freeware to expensive commercial packages. Most of these run on Unix or Linux workstations.  For simplicity (and to avoid instruction in Unix), I’ve designed the course so that you can use the Macintosh computers in the Mac lab, and Matlab as the primary data analysis tool for 2D seismic data.  We will make liberal use of many freeware/shareware data processing and display tools that have been written for Matlab.  Most of these By the end of the course, I want you to be able to receive a digital “SEG-Y” file of a seismic reflection section, read it into Matlab, and display and interpret it.  This is a reasonable goal, even if you have no prior experience in Matlab or reflection seismology.

            For 3D interpretation, we’ll use the OpendTect software, put out by dGB Earth Sciences.  This is remarkable software:  it is free, multi-platform (Mac, Linux, Windows), and user-friendly. 

 

Textbook:

            The textbook for this course is Exploration Seismology, R.E. Sheriff and L.P. Geldart, Cambridge University Press.  Lectures will consist of a mix of material from the textbook and (mostly) elsewhere. The textbook covers many of the key topics in much greater detail than we’ll have time to do in class, so I encourage you to use the book as a resource for filling in background knowledge (it’s especially useful for providing relatively complete mathematical derivations).  Another book you may find useful is Seismic Data Processing, O. Yilmaz, published by the Society of Exploration Geophysicists.

 

Course requirements:

Attendance.  There is no strict attendance policy; however, it is strongly advised that you attend all classes.

 

Grades.  There will be no exams in this class.  Your grade will be based on homework, quizzes, reports of case studies and a written paper.  The quizzes will be unannounced.

 

                        Homework       =   30% of grade

                        Quizzes            =   10%

                        Case Studies   =   30%

                       Term Paper      =   30%

 

Work turned in late without prior consent of the instructor will be penalized 10% per day.

 

Disabilities. If you have a physical, learning, or psychological disability and require accommodations, please let us know as soon as possible.  You will need to register with, and provide documentation of your disability to, University Disability Support Services (UDSS) in SEO, Room 330, Knight Hall, 766-6189, TTY: 766-3073.

 

Students and Teachers Working Together. The College of Arts & Sciences has produced a document called “Students and Teachers Working Together” that describes expectations of both students and faculty regarding such issues as classroom deportment, academic honesty, attendance, office hours, and advising. We encourage you to download this document from the URL listed below and read it carefully.

http://uwadmnweb.uwyo.edu/a&s/Current/2005Stud&TeachersWorking%20Together(7-29-05).doc

Here is the first pargraph of that document, which describes the basic philosophy we will adhere to:

 

“At a good university, good student/teacher relationships come from mutual respect, trust, and honesty. Learning takes place when teachers and students treat each other with politeness and civility, rather than with anger, ridicule, or confrontation. Indeed, a classroom conducive to teaching and learning is the right of all University of Wyoming students and faculty, and it is the responsibility of both parties to achieve and maintain it even though specifics will vary from course to course.”

Lecture Topics (in rough order of presentation)

Matlab Intro

Intro to Reflection Seismology

Wave propagation I

Basic time series analysis

Wave partitioning at an interface

Wave propagation II

Geometry of seismic waves I

Geometry of seismic waves II

Seismic Amplitude and Display

Overview of Processing Steps & Interpretation

Case Study 1:  The Blake Ridge

Elasticity, velocity, density, porosity, attenuation

Geometry

Velocity Analysis & Stacking

Filtering and the Fourier domain

Migration I

Migration II

Case Study 2:  Line Ties and Velocity-Depth Conversion

DMO

PSDM

Deep Crustal and Mantle Reflections

Interpretation:  Pitfalls Ground-Penetrating Radar:  Principles and examples

Case Study 3: GPR Data

Interpretation:  Seismic Stratigraphy etc.

S-wave surveys; Vibroseis

3D seismics: acquisition and processing

3D seismics:  interpretation

Case Study 4:  3D seismic interpretation using OpendTect