Journal: Physics of the Earth and Planetary Interiors

Abbreviation

Phys. earth planet. inter.

Publisher

Elsevier

Journal Volumes

ISSN

0031-9201
1872-7395

Description

Filters

Reset filters

Search Results

Publications1 - 10 of 97
  • Thermal and compositional evolution of the martian mantle
    Item type: Journal Article
    Ruedas, Thomas; Tackley, Paul J.; Solomon, Sean C. (2013)
    Physics of the Earth and Planetary Interiors
  • On the rise of strongly tilted mantle plume tails
    Item type: Journal Article
    Mériaux, C.A.; Mansour, J.A.; Moresi, L.N.; et al. (2011)
    Physics of the Earth and Planetary Interiors
  • Correcting distorted paleosecular variation in late glacial lacustrine clay
    Item type: Journal Article
    Borradaille, G. J.; Almquist, B. S. (2008)
    Physics of the Earth and Planetary Interiors
  • Evidence for melt leakage from the Hawaiian plume above the mantle transition zone
    Item type: Journal Article
    Hier-Majumder, Saswata; Ballmer, Maxim; Agius, Matthew; et al. (2021)
    Physics of the Earth and Planetary Interiors
    Dehydration reactions at the top of the mantle transition zone (MTZ) can stabilize partial melt in a seismic low-velocity layer (LVL), but the seismic effects of temperature, melt and volatile content are difficult to distinguish. We invert P-to-S receiver function phases converted at the top and bottom of a LVL above the MTZ beneath Hawaii. To separate the thermal and melting related seismic anomalies, we carry out over 10 million rock physics inversions. These inversions account for variations arising from the Clapeyron slope of phase transition, bulk solid composition, dihedral angle, and mantle potential temperature. We use two independent seismic constraints to evaluate the temperature and shear wave speed within the LVL. The thermal anomalies reveal the presence of a hot and seismically slow plume stem surrounded by a “halo” of cold and fast mantle material. In contrast to this temperature distribution, the plume stem contains less than 0.5 vol% melt, while the surrounding LVL—within the coverage area—contains up to 1.7 vol% melt, indicating possible lateral transport of the melt. When compared to the melting temperatures of mantle rocks, the temperature within the LVL, calculated from seismic observations of MTZ thickness, suggests that the observed small degrees of melting are sustained by the presence of volatiles such as CO2 and H2O. We estimate the Hawaiian plume loses up to 1.9 Mt/yr H2O and 10.7 Mt/yr CO2 to the LVL, providing a crucial missing flux for global volatile cycles. © 2021 Elsevier B.V. All rights reserved.
  • Thermal and compositional evolution of the martian mantle
    Item type: Journal Article
    Ruedas, Thomas; Tackley, Paul J.; Solomon, Sean C. (2013)
    Physics of the Earth and Planetary Interiors
  • Sound velocities and elasticity of DHMS phase A to high pressure and implications for seismic velocities and anisotropy in subducted slabs
    Item type: Journal Article
    Sanchez-Valle, Carmen; Sinogeikin, Stanislav V.; Smyth, Joseph R.; et al. (2008)
    Physics of the Earth and Planetary Interiors
    Dense hydrous magnesium silicate (DHMS) phase A forms in cold subducted slabs after the breakdown of antigorite serpentine. and may play an important role in the transport of water within the upper mantle. In this paper we present acoustic velocities and the single-crystal elastic properties of Fe-bearing phase A, (Mg-0.981 Fe-0.019)(7)Si2O8(OH)(6), measured by Brillouin spectroscopy on a sample compressed to 12.4(2) GPa in a diamond anvil cell. A fit to the acoustic data using a 3rd order finite-strain EOS yields the following adiabatic bulk (K-S) and shear (mu) moduli and their pressure derivatives: K-S=106(1) GPa, (partial derivative K-S/partial derivative P)(T0)=5.8(3), mu=61(1) GPa, (partial derivative mu/partial derivative P)(T0)=1.8(1). Within the experimental resolution, the pure longitudinal elastic constants, C-11 and C-33, and the off-diagonal C-12 constants exhibit positive linear pressure dependence, whereas C-44, C-66 and C-13 increase with a quadratic dependence on pressure. The axial compressibility of phase A remains highly anisotropic in the investigated pressure range, with the a-axis being 15% more compressible than the c-axis at 12.4(2) GPa. Compared to forsterite, the aggregate compressional (V-P) and shear (V-S) acoustic velocities of phase A are 7% slower at room pressure. Although the velocity contrast diminishes to 3.5% for V-P, it is maintained for V-S over the investigated pressure range. Phase A has high shear wave anisotropy (A(S)) and shear-wave polarization anisotropy (A(S)(P0)) of A(S)=20% and A(S)(P0)=18%, and a more moderate compressional wave anisotropy A(P)=12% at room pressure. The A(P) of phase A decreases to 8% at 12.4(2) GPa, remaining significantly lower than that of forsterite, whereas the shear anisotropy is nearly constant at similar to 20% over the same pressure range and exceeds that of forsterite by 12% at 12.4(2) GPa. At upper mantle pressures, the shear wave splitting in phase A (A(S)(P0)) is 20% higher than in forsterite. The results of this study were used with thermoelastic S data for other relevant minerals to compute the density, seismic velocities and V-P/V-S ratios of subducted garnet-harzbugite and moderately depleted harzburgite assemblages with various degrees of hydration as a function of pressure along a slab isotherm at 1073 K. The results suggest that the seismic velocities of dry and water-saturated harzburgites (44.5vol% phase A) may be indistinguishable at upper mantle P-T conditions because of the increasing concentration of high-pressure orthopyroxene upon hydration. This phase displays high seismic velocities that offset the decrease in velocities due to phase A, rendering hydration difficult to detect (anelastic attenuation is not considered). Combined observations from the analysis of seismic parameters indicate that significant shear wave anisotropy, accompanied by high V-P/V-S and Poisson's ratios and pronounced shear wave splitting, could be major diagnostic features for identifying phase A-bearing assemblages at depth (180-350 km) in cold subducted slabs. (C) 2008 Elsevier B.V. All rights reserved.
  • Modeling mantle convection in the spherical annulus
    Item type: Journal Article
    Hernlund, John W.; Tackley, Paul J. (2008)
    Physics of the Earth and Planetary Interiors
  • A stabilization algorithm for geodynamic numerical simulations with a free surface
    Item type: Journal Article
    Kaus, Boris J.P.; Mühlhaus, Hans; May, Dave A. (2010)
    Physics of the Earth and Planetary Interiors
  • On the statistical significance of correlations between synthetic mantle plumes and tomographic models
    Item type: Journal Article
    Boschi, L.; Becker, Thorsten W.; Steinberger, Bernhard (2008)
    Physics of the Earth and Planetary Interiors
  • Influences of the buoyancy of partially molten rock on 3-D plume patterns and melt productivity above retreating slabs
    Item type: Journal Article
    Zhu, Guizhi; Gerya, Taras; Honda, Satoru; et al. (2011)
    Physics of the Earth and Planetary Interiors
Publications1 - 10 of 97