Congratulations to Bob Liebermann for AGU Edward A. Flinn
III Award!
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Website for the Announcement
Origin of Termal and Compositional
Heterogeneities in the Lower Mantle
The relative changes between shear and compressional velocities (RSP=∂lnVS/∂lnVP), bulk sound and shear velocities(RCS = ∂lnVC/∂ln VS), and density versus shear wave velocity (RrS=∂ lnr/∂lnVS) in response to thermal and chemical variations were investigated for pyrolitic lower mantle. For heterogeneities with thermal origins, RSP increases from 1.7 to 2.0 together with RrS decreasing from 0.4 to 0.2 and RCS = ~0.27 from the top to the bottom of the lower mantle. In comparison, chemical variations (bulk iron or silica contents) are characterized by RSP < 1.5 and RCS > 0.5 at lower mantle depths. Negative values of RrS and RCS are indicative of chemical anomalies in the lower mantle, but a combination of thermal and chemical heterogeneities may be required to produce velocity and density anomalies at the magnitudes observed in seismic data. (link to Li, B. Progress in Natural Science 19,1603-1611)
Equation of State of Bulk Metallic Glass: Compressional (VP)
and shear wave (VS)
velocities
of Zr46Cu37.6Ag8.4Al8
bulk metallic glass (
Thermal Equation of State of
Abstract The pressure–volume–temperature (P–V–T)
relation of CaIrO3 post-perovskite (ppv) was measured at pressures and temperatures up to 8.6 GPa and 1,273 K,respectively,
with energy-dispersive synchrotron X-ray diffraction using a
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