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Research Note: The sensitivity of surface seismic P‐wave data in transversely isotropic media to reflector depth
Author(s) -
Alkhalifah Tariq
Publication year - 2017
Publication title -
geophysical prospecting
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.735
H-Index - 79
eISSN - 1365-2478
pISSN - 0016-8025
DOI - 10.1111/1365-2478.12483
Subject(s) - transverse isotropy , anisotropy , eikonal equation , geology , isotropy , wavelength , reflector (photography) , sensitivity (control systems) , surface wave , optics , seismic wave , geometry , geophysics , seismology , physics , mathematics , light source , electronic engineering , engineering , quantum mechanics
The leading component of the high‐frequency asymptotic description of the wavefield, given by the travel time, is governed by the eikonal equation. In anisotropic media, traveltime measurements from seismic experiments conducted along one surface cannot constrain the long‐wavelength attribute of the medium along the orthogonal‐to‐the‐surface direction, as anisotropy introduces an independent parameter controlling wave propagation in the orthogonal direction. Since travel times measured on the Earth's surface in transversely isotropic media with a vertical symmetry axis are mainly insensitive to the absolute value of the anisotropic parameter responsible for relating these observations to depth δ, the travel time was perturbed laterally to investigate the traveltime sensitivity to lateral variations in δ. This formulation can be used to develop inversion strategies for lateral variations in δ in acoustic transversely isotropic media, as the surface‐recorded data are sensitive to it even if the model is described by the normal moveout velocity and horizontal velocity, or the anellipticity parameter η. Numerical tests demonstrate the enhanced sensitivity of our data when the model is parameterised with a lateral change in δ.