ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Transition region of the earth's upper mantle (1986)
    In:  Nature, Luxembourg, EGS-Gauthier-Villars, vol. 320, no. 6717, pp. 321-328, pp. 2324
    Details
    Publication Date: 1986
    Keywords: Seismology ; Low velocity layer ; Low viscosity zone ; earth mantle
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    BIBLIOGRAPHY SEISMOLOGY
  • 2
    facet.materialart.
    Unknown
    Elasticity of minerals, glasses, and melts (1995)
    American Geophysical Union
    In:  Mineral Physics & Crystallography - A Handbook of Physical Constants, Washington, D.C., American Geophysical Union, vol. 17, no. 16, pp. 303-331, (ISBN 0080419208)
    Details
    Publication Date: 1995
    Keywords: Mineralogy ; Physical properties of rocks ; Review article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    BIBLIOGRAPHY SEISMOLOGY
  • 3
    facet.materialart.
    Unknown
    High-pressure elasticity of serpentine and seismic properties of the hydrated mantle wedge (2013)
    Wiley
    Details
    Publication Date: 2013-01-17
    Description: [1]  A subset of the single-crystal elastic moduli of natural antigorite has been measured using Brillouin scattering at high-pressure up to 9 GPa. Aggregate properties and axial compressibilities are in good agreement with equation-of-state results from X-ray diffraction. Stiffness along the c -axis increases, becoming close to those within the silicate layer near 7 GPa. A slight discontinuity in the evolution of the elastic moduli near 7 GPa is associated with a phase transition. Raman spectroscopy shows the transition does not occur in subducting slabs, except in the core of the coldest slabs where serpentine may be subducted to depths of about 200 km. Varying temperature and pressure has limited effects on the interpretation of seismic velocities, principally because of the limited depth range of serpentine stability (mostly above 100 km depth), and also due to the compensating effects of pressure and temperature that maintain velocity variations well within the uncertainties and statistical variability of seismological studies. Serpentinites are excellent candidates for explaining low velocities in the hydrated mantle wedge, inversion of the Moho, and thin anisotropic low-velocity layers at the plate interface. Serpentinite layers provide an alternative explanation to fluid-saturated oceanic crust for explaining these phenomena, and account for a transition to an aseismic, decoupled plate interface.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 4
    facet.materialart.
    Unknown
    Elasticity of lawsonite and seismological signature of metamorphism and water cycling in the subducting oceanic crust (2013)
    Wiley
    Details
    Publication Date: 2013-12-31
    Description: The elastic properties of lawsonite determined from equations of state, Brillouin scattering, acoustic velocity measurements, and first-principles calculations are reviewed. Equations of state are essential for thermodynamic modelling of phase equilibrium at high pressure. Elastic tensor determinations allow calculating seismic properties of isotropic rocks, and of anisotropic rocks when combined with CPO determinations. Potential effects of low-temperature, high-pressure phase transitions in lawsonite on extrapolations to deep-Earth conditions are discussed. Seismological data suggest that metamorphic zoning in active cold subduction zones can be resolved as low velocity layers down to 250 km. Mineral physics and phase equilibria indicate that lawsonite is the best candidate for explaining such low velocities. These layers are likely the image of water recycling to the deep mantle in subduction zones. This article is protected by copyright. All rights reserved.
    Print ISSN: 0263-4929
    Electronic ISSN: 1525-1314
    Topics: Geosciences
    Published by Wiley
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    Electronic Resource
    Electronic Resource
    The complex mechanical modulus as a structural probe: The case of alkali borate liquids and glasses (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 103 (1995), S. 9907-9917 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Brillouin light scattering has been used to determine the high-frequency complex mechanical modulus of alkali borate liquids and glasses, as a function of the temperature. The temperature dependence of the complex modulus can be described by an enhanced Maxwell model for linear viscoelastic systems. Accordingly, the module comprises relaxational components and a temperature dependent static modulus, which is determined by the equilibrium volume fraction of kinetically arrested domains. Application of this model to the Brillouin data indicates that the structural relaxations in undercooled glass forming liquids occur via relatively distinct mechanisms, each one becoming thermally activated within a different temperature range. The rate of degradation of the network structure increases with increasing alkali content, and is commensurate of the fragility of the liquid. The structural features which are subject to a change in the context of a particular degradation mechanism are released sequentially, i.e., relaxation, facilitated by the rupture of a given network link, is required before other links of the same type become affected by thermal motion. Mechanisms that are activated at high temperatures involve the diffusional displacements of various atomic species. Immediately above Tg, however, structural relaxations are characterized by the dominance of the bulk viscosity over the shear viscosity, and by positive values of the imaginary part of the complex Poisson ratio. This indicates that, to a significant degree, compressive deformations and head-on collisions between structural moieties are involved in the structural relaxations at these low temperatures. It is surmised that the deformation of boroxol rings, where a boron moves out of the BO3 plane to exchange one of its oxygen neighbors, is underlying to this relaxation mechanism, which results in an increase of the average network ring size. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.469880
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Elastic properties of orthorhombic KNbO3 single crystals by Brillouin scattering (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 6603-6608 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Brillouin light scattering was used to obtain elastic and piezoelectric constants for a single domain orthorhombic KNbO3 single crystal at room temperature and pressure. More than 320 measurements of longitudinal and transverse acoustic wave velocities were obtained in 160 different crystallographic directions. An inversion of these data using the literature values for the dielectric permittivity of KNbO3 resulted in the full set of elastic and piezoelectric constants for the material. It is suggested that the difference between piezoelectric constants obtained by high- and low-frequency methods could be explained by the high-frequency relaxation-type dispersion for the dielectric constant ε33 in the GHz region by analogy with BaTiO3. The directional dependence of electromechanical coupling for longitudinal and transverse acoustic waves in KNbO3 was analyzed. The obtained elastic constants were (in GPa): CE11=224(4), CE22=273(5), CE33=245(5), CE44=75(1), CE55=28.5(5), CE66=95(2), CE12=102(5), CE13=182(10), CE23=130(6), where E denotes constant electric field strength.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.355099
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Pressure dependence of optical absorption in PbTiO3 to 35 GPa: Observation of the tetragonal-to-cubic phase transition (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 3705-3707 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Optical absorption of the polar material PbTiO3 has been studied up to 35 GPa (350 kbar) in the visible range of wavelengths using a single crystal samples compressed in a diamond anvil high pressure cell. The absorption edge shifts toward lower energies with increasing pressure. Pressure dependence of the absorption edge undergoes significant changes at about 11.5±0.3 GPa, close to the previously identified tetragonal-cubic phase transition. The change in pressure dependence of the spectra is consistent with second-order character of the transition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.352315
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Orthorhombic perovskite CaTiO3 and CdTiO3: structure and space group (1987)
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 43 (1987), S. 1668-1674 
    Details
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108270187090620
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Sound velocities and elasticity of cordierite and implications for deep crustal seismic anisotropy (1999)
    Springer
    Physics and chemistry of minerals 26 (1999), S. 333-343 
    Details
    ISSN: 1432-2021
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Abstract  The elastic properties of cordierite, a common volatile-bearing metamorphic mineral, were measured using Brillouin spectroscopy under ambient conditions. We obtain a bulk modulus of KS =129(1) GPa, and a shear modulus of G=54.0(4) GPa. The bulk modulus of cordierite is much larger than those of other crustal framework silicates (e.g., quartz and feldspars), but is similar to KS for denser upper mantle phases such as olivine. This is likely a result of the cordierite crystal structure, as suggested by a similarly high value of KS for minerals with closely related structures. Cordierite has an unusually high K/G ratio of about 2.4, and a Poisson’s ratio of 0.31,which may be a diagnostic seismic properties of areas in which cordierite-rich metamorphic rocks occur. The overall velocity anisotropy of cordierite is relatively low (〈14%) in comparison with many other metamorphic minerals. Calculated velocities for a representative lower crustal rock suggest that cordierite is not likely to explain the high seismic anisotropy observed in some lower crustal sections. Cordierite would have a strong influence on the bulk seismic anisotropy only in rocks where it is present in large concentrations and has a strong preferred orientation. Although such rocks are known to occur, they are uncommon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002690050193
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Single-crystal elastic properties of chondrodite: implications for water in the upper mantle (1999)
    Springer
    Physics and chemistry of minerals 26 (1999), S. 297-303 
    Details
    ISSN: 1432-2021
    Keywords: Key words Elasticity ; Chondrodite ; Brillouin scattering ; Hydrous minerals ; Mantle volatiles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Abstract  Chondrodite, a member of the humite group of minerals, forms by hydration of olivine and is stable over a range of temperatures and pressures that includes a portion of the uppermost mantle. We have measured the single crystal elastic properties of a natural chondrodite specimen at ambient conditions using Brillouin spectroscopy. The isotropic aggregate bulk (K) and shear (µ) moduli calculated from the single-crystal elastic moduli, Cij, are: KS=118.4(16) GPa and µ=75.6(7) GPa. A comparison of the structures and elasticity of olivine and chondrodite indicate that the replacement of O with (OH,F) in M2+O6 octahedra has a small effect on the elasticity of humite-group minerals. The slightly diminished elastic moduli of humite-group minerals (as compared to olivine) are likely caused by a smaller ratio of strong structural elements (SiO4 tetrahedra) to weaker octahedra, and perhaps a more flexible geometry of edge-sharing MO4(O,OH,F)2 octahedra. In contrast to the humite-olivine group minerals, the incorporation of water into garnets and spineloids leads to a more substantial decrease in the elastic properties of these minerals. This contrasting behavior is due to formation of O4H4 tetrahedra and vacant hydroxyl-bearing octahedra in the garnets and spineloids, respectively. Therefore, the mechanism of incorporation of H/OH into mineral phases, not only degree of hydration, should be taken into account when estimating the effect of water on the elastic properties of minerals. The bulk elastic wave velocities of chondrodite and olivine are very similar. If humite-like incorporation of OH is predominant in the upper mantle, then the reaction of OH with olivine will have a minor or possibly no detectable effect on seismic velocities. Thus, it may be difficult to distinguish chondrodite-bearing rocks from “anhydrous” mantle on the basis of seismically determined velocities for the Earth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002690050189
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...