## SOEE3530 Global Geophysics

### 10 creditsClass Size: 30

Module manager: Dr Christopher Davies
Email: C.Davies@leeds.ac.uk

Taught: Semester 2 (Jan to Jun) View Timetable

Year running 2022/23

This module is not approved as a discovery module

### Objectives

This module focuses on the earth's deep interior and combines different geophysical methods to investigate this area.

By the end of the module the student will have a good picture of the physical properties, structure and dynamics of the deep earth, and how we can deduce these features from geophysical techniques.

Much of the emphasis is on problem solving, so the student will master various advanced mathematical techniques for quantitatively analysing geophysical data.

Learning outcomes
On successful completion of this module students should be able to:

-Apply detailed mathematical analysis combined with order of magnitude estimates to quantitatively analyse a range of problems in geodynamics.
-Analyse and evaluate the different perspectives of the dynamics of Earth's interior using research literature.
-Describe Earth's structure and constitution.

### Syllabus

Plate Tectonics:
- Plate characteristics; historical development of observational evidence, continental drift & sea floor spreading
- Relative plate motions in 2D, velocity diagrams and triple junction analysis
- Relative plate motions in 3D, rotation vectors, geometric implications of motion on a sphere
- Plate driving forces, traction, ridge push, slab pull, phase boundary effects

Mantle Convection:
- Governing equations, Boussinesq approximation
- Non-dimensional numbers, scaling laws
- Onset of convection, critical Rayleigh number
- Fate of slabs, whole mantle vs layered convection
- Dynamic topography
- The adiabat and mantle geotherm

Geomagnetic Field:
- Spherical harmonics
- IGRF
- Dipole strength, long term variations, CALS7k, GUFM; dipole decay
- Geodynamo, governing equations, non-dimensional numbers,
- Core convection and magnetic field generation

### Teaching methods

 Delivery type Number Length hours Student hours Lecture 20 1.00 20.00 Practical 10 1.00 10.00 Private study hours 70.00 Total Contact hours 30.00 Total hours (100hr per 10 credits) 100.00

### Private study

- Completion of coursework problems (1.5 x 10 hours).
- Literature review and completion of essays (2 x 8 hours).
- General background reading for lectures (10 x 1 hours).
- Exam preparation and revision (1 x 29 hours).

### Opportunities for Formative Feedback

Continuous monitoring during practicals with immediate formative assessment and feedback.

Coursework consists of formatively assessed weekly problem sets and two essays. One essay is formatively assessed and the other is summatively assessed. The second essay is an expanded version of the first essay and both cover similar topics.

Assessments consist of a mix of numerical questions and a discursive essay on topics that will be similar to those on the final exam.

### Methods of assessment

Coursework
 Assessment type Notes % of formal assessment Practical Summative assessment comprises 1 practical report. Weekly problem sets are formatively assessed 50.00 Total percentage (Assessment Coursework) 50.00

Normally resits will be assessed by the same methodology as the first attempt, unless otherwise stated

Exams
 Exam type Exam duration % of formal assessment Open Book exam 48 hr 00 mins 50.00 Total percentage (Assessment Exams) 50.00

Normally resits will be assessed by a single 2 hour exam.