Introduction

This lecture includes a general introduction, recalling the existence of plate tectonics and underlying mantle convection, and illustrating the different types of crustal and lithospheric deformation associated with internal dynamics and observed at the Earth's surface, mainly at plate boundaries. We then review the different types of deformation: elastic, plastic and brittle, and formulate the relationships between the corresponding stresses and strains, and in the case of plastic deformation, the laws of creep. We introduce the tools of global seismology for observing and measuring seismic anisotropy at the macroscopic scale, then introduce the main constituents of mantle rocks as a function of depth. Finally, we introduce the different scales at which we will examine elastic anisotropy: the crystal scale, the rock scale and the scale of geophysical observations.