Special Topics in Geophysics--Introductory Subduction Zone Geodynamics
Lecturer: Prof. Kelin Wang (Geological Survey of Canada & Univ. of Victoria)
Dates: June 21 – July 7, Mon, Wed, Fri (3, 4, 5); Classroom: 5405
Credit: 1 (20 lectures); Language: English
Contents: This short course is aimed at graduate students with some training in geophysics. It introduces the basic observational and theoretical frameworks of the geodynamics of subduction zones, as well as major developments in the 21st century that are not yet reflected in text books. An overview of plate tectonics and basic processes during plate subduction will be provided. Emphasis will be given to thermal and mechanical processes, the subduction fault, and earthquake deformation. Geochemistry is not covered, although there will be limited reference to petrology.
Prerequisites: Knowledge of plate tectonics, structural geology, seismology, and solid mechanics; familiarity with calculus and partial differential equations.
Methods of teaching: There will be about 20 45-minute lectures. In addition, students are guided to read published materials, search information on selected topics, and give summary oral presentations in class (10-20 minutes, organized in small groups). Classroom discussion is also an important part of the study.
- Plate tectonics overview: ~2 lectures. Earth structure, heat flow, plate boundaries, plate motion, tectonic forces, seismic and tsunami hazards.
- The oceanic plate: ~5 lectures. Thermal evolution, hydrothermal processes, plate flexure, lithospheric rheology and strength. (Assignment 1)
- The slab, forearc, arc, and backarc: ~3 lectures. Thermal regime, metamorphic petrology, volcanism, intraslab earthquakes.
- The megathrust: ~6 lectures. Megathrust earthquakes, coseismic deformation, forearc stress and megathrust strength, stick-slip and creep, friction and energy budget, tremor and slow slip. (Assignment 2)
- Deformation cycles of subduction earthquakes: ~4 lectures. Viscoelasticity, postseismic and interseismic deformation, deformation models.
Assignments and exams: There will be two assignments (involving simple calculation with provided codes). There will be assigned reading materials, followed by classroom discussions. The final exam will be in the form of a short classroom presentation (by group representatives). There will be no written final exam.
Method of evaluation: Assignment 50%; participation in classroom discussion 20%; final presentation 30%. Specific requirements for each of the three components will be given later.