GS525-1998: Tectonophysics -- Course Outline



Topics, Background reading, Homework



The three types of plate boundaries; Sea-floor spreading and divergent boundaries, how we measure spreading rates, what parameters are used as input, what evidence is important; Transform faults, seismic focal mechanisms; Convergent boundaries; Displacement vectors on a sphere, Euler poles; Geomagnetism and the Geomagnetic Polarity Time Scale; Paleomagnetism and apparent polar wander paths; Hot spots; Reference frameworks, true polar wander (TPW)


Week 1: Fowler's Chapters 1, 2, 3;

for Friday September 18 special reading Gordon (1995, Rev. Geophys. v. 100, 24,367-24,392)

Weeks 2 and 3: Fowler's chapters 4, 5

Homework: Gravitational attraction and gravitational potential: a pointmass, a sphere, a hollow shell, an ellipsoidal figure (reference spheroid), a potato-shaped real earth, the geoid

Moments of inertia and relationship to gravitational potential and TPW

gravity anomalies, isostasy



Heat transport mechanisms: conduction, convection, and radiation.

Generation of heat: accretion, radiogenic decay, tidal heating.

Present day heat flow from the Earth (Pollack et al., 1993)

Plate tectonics and mantle convection.

Plumes, Richter rolls and other secondary (?) phenomena

Thermal history of the Earth's interior.

A planetary perspective: size matters.

Reading : Fowler Chapter 7 (section 1 through 8); Pollack, H.N., S.J. Hurter, and J.R. Johnson, "Heat flow from the Earth's interior: analysis of the global data set." Rev. Geophys., 31, 267-280, 1993.



Week 1 (2 lectures + 1 discussion section on stress/strain measurement)

Tensors: Definitions/Notation, Principal Components

Stress and Strain: Definitions, Math. and Intuitive Representation, Measurement in Geologic Context

Mechanical Equilibrium: Derivation of Fundamental Equations

Week 2 (2 lectures + 1 discussion section on global earth structure)

Elasticity. Linear: Stress-Strain Relationship, The Elastic Wave Equation, Elasticity of Composites, Anisotropy and

Anelasticity, Finite Strain, Reference Frames

Global Earth Structure: Body Waves/Surface Waves/Free Oscillations, 1-D Models, Tomography

Week 3 (2 lectures + 1* discussion section on rheological models)

Fluid Mechanics: Material Derivative, Conservation Equations, Applications (Stokes, R-B linear stability problems)

Rheology: Macroscopic Picture, Maxwell Relaxation Time, Non-Newtonian,

Microscopic Picture: Defects and Dislocations, Dynamics



Week 1 Brittle and Plastic Deformation: mechanics of faulting, microcracks, crystal plasticity, brittle-plastic transition

Reading: from Scholz's "Mechanics of earthquakes and faulting", Chapter 4

Week 2 Geologic processes at plate boundaries: divergent, convergent, transform.

Reading: Fowler's Chapters 8 and 9




Week 1 (2 lectures + 1 discussion) Mantle Convection

Fowler's (Chapter 7, section 7.8)

Governing Equations, Relevant Parameter space for the Earth's mantle, Scales of mantle convection, Models of mantle convection (numerical and laboratory experiments)

Discussion: focusing on current models of mantle convection and imaging from seismology

Week 2 (2 lectures) Plate Tectonics and Mantle Convection

Fowler's (Chapter 7 section 7.10)

Plate Driving Mechanism: Traditional models of plate driving forces, "Fluid dynamical" models of plate driving forces, Balance of forces

Plate motions and changes in plate motions: Dynamical consequences and causes

Plate boundary and plate deformation: Intraplate stresses

Week 3 (2 lectures + discussion) Dynamic topography and basin formation

Fowler's (Chapter 5, section 5.7)

Dynamic topography and the geoid: Present-day geoid and dynamic topography, Sea-level record and continental flooding, Impact on climatic events?

Plate flexure and basin formation: Definitions and relevant equations, Definitions of the lithosphere (elastic, mechanical thermal, etc), Sediment loading

Discussion on: comparing geological record and geophysical observations with dynamical models

Geoid and tpw: flooding record on continents, plate motions



Lithospheric processes: formation of continents, plate collision, delamination, etc.

Reading: Fowler's Chapter 9. Burg and Ford's "Orogeny through time", Chapter 1.

Capstone lecture: A definition of Tectonophysics.

Evaluation, Exam