Inversion for weak triclinic anisotropy from acoustic axes

0397121 - GFÚ 2014 RIV NL eng J - Článek v odborném periodiku
Vavryčuk, Václav
Inversion for weak triclinic anisotropy from acoustic axes.
Wave Motion. Roč. 50, č. 8 (2013), s. 1271-1282. ISSN 0165-2125. E-ISSN 1878-433X
Grant CEP: GA AV ČR IAA300120801
Institucionální podpora: RVO:67985530
Klíčová slova: acoustic axis * weak anisotropy * elastic waves * wave polarization
Kód oboru RIV: DC - Seismologie, vulkanologie a struktura Země
Impakt faktor: 1.303, rok: 2013

Acoustic axes are directions in anisotropic elastic media, in which phase velocities of two or three plane waves (P, S1 or S2 waves) coincide. Acoustic axes are important, because they can cause singularities in the field of polarization vectors and anomalies in the shape of the slowness surface. The maximum number of acoustic axes in triclinic anisotropy is 16, and their directions depend on anisotropy parameters in a complicate way. Under weak anisotropy approximation this dependence simplifies and the directions of acoustic axes can be used for the inversion for anisotropy parameters. The maximum acoustic axes under weak anisotropy is 16, the minimum number of acoustic axes is zero. In the inversion, we can retrieve 13 combinations of anisotropy parameters provided we use directions of 7 acoustic axes at least. Under weak anisotropy approximation, the directions of acoustic axes are insensitive to strength of anisotropy; hence we cannot invert for absolute values of weak anisotropy parameters, but only for their relative values.
Trvalý link: http://hdl.handle.net/11104/0224756