Seismic Determination of Elastic Anisotropy and Mantle Flow
- 27 August 1993
- journal article
- other
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 261 (5125) , 1159-1162
- https://doi.org/10.1126/science.261.5125.1159
Abstract
When deformed, many rocks develop anisotropic elastic properties. On many seismic records, a long-period (100 to 250 seconds), "quasi-Love" wave with elliptical polarization arrives slightly after the Love wave but before the Rayleigh wave. Mantle anisotropy is sufficient to explain these observations qualitatively as long as the "fast" axis of symmetry is approximately horizontal. Quasi-Love observations for several propagation paths near Pacific Ocean subduction zones are consistent with either flow variations in the mantle within or beneath subducting plates or variations in the direction of fossil spreading in older parts of the Pacific plate.Keywords
This publication has 20 references indexed in Scilit:
- Upper mantle anisotropy and coupled-mode long-period surface wavesGeophysical Journal International, 1993
- Upper mantle anisotropy in the S.W. Pacific from earthquake travel-time analysisPhysics of the Earth and Planetary Interiors, 1993
- Surface waves in weakly anisotropic structures: on the use of ordinary or quasi-degenerate perturbation methodsGeophysical Journal International, 1989
- The anisotropic structure of the upper mantle in the PacificGeophysical Journal International, 1989
- Implications for continental structure and evolution from seismic anisotropyNature, 1988
- Compressional and shear wave anisotropy in the oceanic lithosphere - the Ngendei seismic refraction experimentGeophysical Journal International, 1986
- Horizontal shear flow in the mantle beneath the Tonga arcNature, 1986
- Surface-wave propagation in an ocean basin with an anisotropic upper mantle: observations of polarization anomaliesGeophysical Journal International, 1981
- Surface-wave propagation in an ocean basin with an anisotropic upper mantle: numerical modellingGeophysical Journal International, 1981
- Parametrically simple earth models consistent with geophysical dataPhysics of the Earth and Planetary Interiors, 1975