Anisotropy of magnetic susceptibility of quaternary lava flows from the East Carpathians

摘要

The traveling times of the seismic rays are measured experimentally as functions of the radial angle at the Earth" centre.These measurements are used to derive information about the velocities of the seismic waves inside the Earth, making use of the Herglotz-Wiechert equation.It is well known that the velocity of the seismic waves increases with depth.We assume a simple linear model of in-depth velocities profile and derive analytical forms for the rays"trajectories, both for a spherical model of Earth and a medium with a plane surface.The trajectories"equations enable us to compute the traveling times, the penetration depth and the distance covered by rays on the surface.The corrections to the traveling times arising from the depth of the seismic focus are also computed.The comparison of our analytical results with well-known experimental data of traveling times is satisfactory, which may validate the velocities model.