Detecting seismic anisotropy above the 410 km discontinuity using reflection coefficients of underside reflections
نویسندگان
چکیده
منابع مشابه
The Effect of H2O on the 410-Kilometer Seismic Discontinuity.
The 410-kilometer seismic discontinuity is generally considered to be caused by a phase transformation of the main constituent of the upper mantle, olivine, alpha-(Mg,Fe)(2)SiO(4), to beta-(Mg,Fe)(2)SiO(4). Recent data show that H(2)O dissolves in olivine and other nominally anhydrous mantle minerals and that the partitioning of H(2)O between olivine and beta-(Mg,Fe)(2)SiO(4) is about 1:10. Suc...
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[1] High-pressure assemblages of subducted oceanic crust are denser than the normal upper mantle but less dense than the uppermost lower mantle. Thus subducted oceanic crust may accumulate at the base of the upper mantle. Direct observational evidence for this hypothesis, however, remains elusive. We present an analysis of a negativepolarity shear wave converted from compressional wave at a sei...
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The complete set of elastic stiffness coefficients of a single crystal of Mg,SiO, in the modified spine1 (wadsleyite) structure are reported at eight pressures from ambient to 14 Gigapascals (GPa). All moduli vary linearly with pressure within the resolution of the data. Third-order Birch-Mumaghan equation fits to aggregate elastic moduli yield values of 170 (k 2) GPa and 4.3 (k 0.2) for the ad...
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Receiver functions calculated from a ten-station subset of the Earthscope Transportable Array (TA) show a well-defined 45 km thick low-velocity layer atop the 410-km discontinuity (“410”) beneath the Tucson, Arizona, region. This observation is consistent with a previously detected layer of increased electrical conductivity in the same region, from which the existence a 5-30 km thick layer of p...
متن کاملAppraising the reliability of converted wavefield imaging: application to USArray imaging of the 410-km discontinuity
S U M M A R Y We develop a generic method to appraise the reliability of wavefield imaging methods and use it to validate some novel observations on the 410-km discontinuity. The core concept of the error appraisal method is to produce a simulated data set that replicates the geometry of the real data. Here we implemented two simulation methods: (1) flat layer primary P to S conversions, and (2...
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ژورنال
عنوان ژورنال: Physics of the Earth and Planetary Interiors
سال: 2018
ISSN: 0031-9201
DOI: 10.1016/j.pepi.2017.12.001