Section A
Q1. Derive Adams–Williamson equation and its application in Geophysics. Also give variation of Body-wave velocity (α) in the Earth's interior according to Earth Model IASP91.
(a) State Fermat's principle and derive Snell's law using the same principle for geometry of incident and refracted ray on horizontal interface.
(b) Write down the condition under which the magnetic dipole is presumed to be a point or isolated pole. Draw the magnetic effects in terms of H, Z and F profiles due to an isolated pole for I = 45\circ, where I is the field inclination.
(c) The diagonal elements of a covariance matrix computed for a linearized inverse problem having model parameters m1, m2, m3, m4, m5 are 49, 15, 3, 200, 40 respectively. Compute the standard deviation in the estimation of model parameter m4.