Earthquake Engineering GE / CEE - 479/679 Lecture 2. Plate Tectonics January 24, 2008. John G. Anderson Professor of Geophysics. Handout Today. Chapter 2. Plate Tectonics Students are advised to read this as your textbook on this topic. Solve exercises 3, 4, 5, 6, and 8.
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
John G. Anderson
Professor of Geophysics
Lithosphere - "rock-sphere" - rigid layer (includes crust)
Asthenosphere - "weak-sphere" (lower v seismic waves) Convection currents flow in the 'plastic' asthenosphere, and the plates of the lithosphere ride on these.
Mantle - iron-rich, mainly solid rock
Outer core - liquid iron and nickel
Inner core - solid iron, nickel
Distances are in kilometers.
Direct measurement using the Global Position Systemhttp://topex.ucsd.edu/marine_topo/gif_images/global_topo_small.gif
Distance between two points on the Earth’s surfacehttp://topex.ucsd.edu/marine_topo/gif_images/global_topo_small.gif
(φ, ψ) = (latitude, longitude) of selected point on plate boundary
(φ1, ψ1) = (latitude, longitude) of pole of relative rotation
uhttp://topex.ucsd.edu/marine_topo/gif_images/global_topo_small.gif = relative rate of plate motion
a = radius of Earth, 6370 km
Δ = distance from pole of rotation, in degrees
ω = rotation rate of plates about their pole
(a different use of the symbol ω)
= 4*1011 dyne/cm2 * 200 km * 40 km * (105 cm/km)2 * 890 cm
= 2.8 * 1028 dyne-cm
=2.8 * 1028 dyne-cm
MW=(2/3) log M0-10.73
Conclusion, by these assumptions, there is enough strain accumulated to cause a MW=8.2 earthquake under Tokyo.