Module Details

The information contained in this module specification was correct at the time of publication but may be subject to change, either during the session because of unforeseen circumstances, or following review of the module at the end of the session. Queries about the module should be directed to the member of staff with responsibility for the module.
Title GEOPHYSICAL DATA MODELLING
Code ENVS586
Coordinator Prof RT Holme
Earth, Ocean and Ecological Sciences
R.T.Holme@liverpool.ac.uk
Year CATS Level Semester CATS Value
Session 2020-21 Level 6 FHEQ First Semester 15

Aims

Ability to create of geophysical models from data.

Practical experience in inversion of mathematically linear problems with knowledge of how to approach more general nonlinear problems.

Understanding of the limitations of such models and how they should be interpreted, with particular reference to model non-uniqueness and instability.

Optimisation theory and its application to interpretation of geophysical models.

Integration of concepts of resolution and error estimation for practical problems.

Time series analysis with non-Fourier methods. Understanding of basic statistics, confidence, implications of hypothesis testing.


Learning Outcomes

(LO1) Knowledge and understanding of    eigenvalue analysis and its application to data analysis; implications of model existence, uniqueness for interpretation; basic statistics, including confidence testing, central limit theory

(LO2) Interpretation of statistical results, geophysical modelling of real data set, amd understanding and application of concepts of resolution, error estimation, and quantification of model quality (and of its limitations.

(LO3) Inverting a large data set to give a geophysical model, and time series analysis from optimisation.

(LO4) Programming skills, including fluency in a unix/linux operating system, and shell programming.

(S1) Problem solving skills

(S2) Numeracy

(S3) Communication skills

(S4) IT skills


Syllabus

 

Optimisation, including Lagrange multipliers;

Mathematical methods problem session;

Eigenvalues and eigenvectors, particularly of real symmetric matrices;

Mathematical methods problem session;

Error analysis and basic probability and statistics. The Normal distribution and Central Limit Theorem;

Central limit theorem demonstration practical;

Hypothesis testing, regression, Chi-squared;

Least squares application to a geophysical problem;

Introduction to inversion through linear algebra;

The generalised matrix inverse;

Least-squares inversion worked examples;

Philosophy of inverse theory: existence, uniqueness, construction and stability;

Least-squares foundations of the generalised inverse;

Least squares inversion worked examples;

Practical solution: Ranking and winnowing, regularisation. Numerical methods (Cholesky decomposition);

Data error covariance. A priori model covariance. Solution resol ution and covariance;

Project session one - Introduction to problem and solution formation;

Interpretation through framing the inverse problem as an optimisation problem - impliations for error estimates and practical bounds on results. Introduction of hypothesis testing as an appropriate solution to this problem;

Alternative methods of error estimation - bootstrapping;

Project session two. Solution space investigation;

Examples of hypothesis testing applied to inverse theory;

Introduction to non-linear inversion, including simulated annealing Outliers;

Project session three: Resolution, covariance, the Eigen problem;

Earthquake location - worked example;

Introduction to tomography as a non-linear inverse problem.

Splines:

Non-linear inversion example;

Practical examples of inverse theory;

Time series analysis with optimisation - splines;

Advanced topics:

Time series analysis with splines


Teaching and Learning Strategies

Teaching Method 1 - Lecture
Description: Basic background and skills instruction
Attendance Recorded: Yes

Teaching Method 2 - Laboratory Work
Description: Neptune practical and spline exercise included
Attendance Recorded: Yes
Unscheduled Directed Student Hours (time spent away from the timetabled sessions but directed by the teaching staff): 24


Teaching Schedule

  Lectures Seminars Tutorials Lab Practicals Fieldwork Placement Other TOTAL
Study Hours           36

12

48
Timetable (if known)              
Private Study 102
TOTAL HOURS 150

Assessment

EXAM Duration Timing
(Semester)
% of
final
mark
Resit/resubmission
opportunity
Penalty for late
submission
Notes
Final examination Assessment Schedule (When) :1  2 hours    50       
CONTINUOUS Duration Timing
(Semester)
% of
final
mark
Resit/resubmission
opportunity
Penalty for late
submission
Notes
Spline modelling There is a resit opportunity. Standard UoL penalty applies for late submission. This is an anonymous assessment. Assessment Schedule (When) :Week 11/12  Report on spline mod    10       
Neptune magnetic field modelling There is a resit opportunity. Standard UoL penalty applies for late submission. This is an anonymous assessment. Assessment Schedule (When) :Approximately week   1000 words on Neptun    30       
Problem sheets There is a resit opportunity. Standard UoL penalty applies for late submission. This is not an anonymous assessment. Assessment Schedule (When) :Broadly weeks 1, 3, 5, 10, 12  5 problem sheets    10       

Recommended Texts

Reading lists are managed at readinglists.liverpool.ac.uk. Click here to access the reading lists for this module.