The first lecture provided a brief reminder of the wave equation and its solutions in an isotropic or anisotropic elastic medium, as well as the different types of seismic waves, and grape theory, which makes it possible to follow the path of high-frequency waves in an earth model. We introduced the concept of a global reference model (" 1D ") and the principle of seismic tomography, which relies above all on measuring the travel times of different seismic waves and calculating the differences - or residuals - between the measured times and the times calculated in an existing earth model (as accurate as possible). With a set of paths illuminating the mantle or parts of it in different directions, all these residuals are then backpropagated to determine the location, shape and amplitude of elastic structure anomalies. We have posed the corresponding system of equations and introduced the notions of " direct problem " and " inverse problem ".
16:00 - 18:00
