Computing relative plate velocities: A primer

Standard models of present-day plate motions are framed in terms of rates and poles of rotation, in accordance with the well-known theorem due to Euler. This article shows how computation of relative plate velocities from such models can be viewed as a simple problem in spherical trigonometry. A FORTRAN subroutine is provided to perform the necessary computations.EDITOR'S NOTE: Teaching geomathematics and geostatistics is a particularly difficult task. It requires a good knowledge of the mathematical theory and of its applications in the earth sciences. Good textbooks are relatively rare. So finding suitable examples and easy-to-follow proofs is time-consuming.This Teacher's Aide Column has been initiated to help get teaching material into circulation, and to act as a forum for exchanging questions and answers. Readers' suggestions are most welcome.Margaret ArmstrongAssociate Editor