Weak-anisotropy moveout approximations for P-waves in homogeneous TOR layers

0476309 - GFÚ 2018 RIV US eng J - Journal Article
Farra, V. - Pšenčík, Ivan
Weak-anisotropy moveout approximations for P-waves in homogeneous TOR layers.
Geophysics. Roč. 82, č. 4 (2017), WA23-WA32. ISSN 0016-8033. E-ISSN 1942-2156
R&D Projects: GA ČR(CZ) GA16-05237S
Institutional support: RVO:67985530
Keywords : anisotropic media * velocity * seismic waves
OECD category: Volcanology
Impact factor: 2.368, year: 2017

We have developed approximate P-wave reflection moveout formulas for a homogeneous layer of orthorhombic symmetry overlying a horizontal or dipping reflector. The symmetry planes of an orthorhombic medium in the layer can be arbitrarily oriented. The formulas are based on the weak-anisotropy approximation. Thus, their accuracy depends not only on the strength of anisotropy, but also on the deviations of the phase and ray velocities. Nevertheless, the performed tests indicate that for P-wave anisotropy of approximately 25%, the maximum relative traveltime errors of the formulas do not exceed 3%. The formulas are expressed in terms of six P-wave weak-anisotropy parameters and three Euler angles specifying the orientation of the symmetry planes of the orthorhombic medium. In the case of a dipping reflector, the formulas also depend on the apparent dip angle of the reflector.
Permanent Link: http://hdl.handle.net/11104/0272844