Open AccessAnisotropy in the lowermost mantle beneath the I ndian O cean G eoid L ow from ScS splitting measurements
Author(s) -
Padma Rao B.,
Ravi Kumar M.,
Singh Arun
Publication year - 2017
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1002/2016gc006604
Subject(s) - geology , anisotropy , seismic anisotropy , isotropy , geoid , mantle (geology) , subduction , geophysics , seismology , physics , tectonics , optics , measured depth
The Indian Ocean Geoid Low (IOGL) to the south of Indian subcontinent is the world's largest geoid anomaly. In this study, we investigate the seismic anisotropy of the lowermost mantle beneath the IOGL by analyzing splitting of high‐quality ScS phases corrected for source and receiver side upper mantle anisotropy. Results reveal significant anisotropy ( ∼ 1.01 % ) in theD ′ ′layer. The observed fast axis polarization azimuths in the ray coordinate system indicate a TTI (transverse isotropy with a tilted axis of symmetry) style of anisotropy. Lattice Preferred Orientation (LPO) deformation of the palaeo‐subducted slabs experiencing high shear strain is a plausible explanation for the observed anisotropy beneath the IOGL.