Aleksandrov Pavel N. RussiaMoscowCenter Geoelectromagnetic studies at the Institute of physics of the earth Schmidt of the Russian Academy of Sciences, 10, Bolshaya Gruzinskaya Str., Moscow, 123242, Russiaalexandr@igemi.troitsk.ru Author's articles A New Approach to the Derivation of Eikonal for Inhomogeneous Anisotropic Elastic Media