Search Results - (Author, Cooperation:T. Spohn)

Showing 1 - 19 results of 19, query time: 0.29s Refine Results
  1. 1
    J. P. Bibring ; M. G. Taylor ; C. Alexander ; U. Auster ; J. Biele ; A. E. Finzi ; F. Goesmann ; G. Klingelhoefer ; W. Kofman ; S. Mottola ; K. J. Seidensticker ; T. Spohn ; I. Wright
    American Association for the Advancement of Science (AAAS)
    Published 2015
    Staff View
    Publication Date:
    2015-08-01
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Published by:
    http://www.aaas.org/

    Latest Papers from Table of Contents or Articles in Press
  2. 2
    Staff View
    Publication Date:
    2015-08-01
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Published by:
    http://www.aaas.org/

    Latest Papers from Table of Contents or Articles in Press
  3. 3
    Staff View
    Publication Date:
    2015-08-01
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Published by:
    http://www.aaas.org/

    Latest Papers from Table of Contents or Articles in Press
  4. 4
    Yinting, Li ; Spohn, T.

    Oxford, UK : Blackwell Publishing Ltd
    Published 1991
    Staff View
    ISSN:
    1365-246X
    Source:
    Blackwell Publishing Journal Backfiles 1879-2005
    Topics:
    Geosciences
    Notes:
    Within the mushroom-shaped head of a cylindrical mantle plume melting occurs, the melt segregates from the matrix, and the matrix deforms and spreads laterally. These processes have been studied with a model of two-phase flow with melting. After characteristics of the solution near the axis of symmetry of the plume were found, a set of asymptotic relations for the variables along the symmetry axis was derived from McKenzie's equations for conservation of mass, momentum and energy of a two-phase system. The distribution of porosity along the plume axis and the vertical and radial segregation velocity of the melt in the vicinity of the axis of symmetry were obtained as functions of depth. Our analytic results show that within the head of a cylindrical mantle plume the contribution of the deformation of the matrix to the total non-hydrostatic pressure gradient cannot be neglected, and melt convergence or divergence is controlled by the radial scale of the upward velocity profile at the depth of the beginning of melting.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1111/j.1365-246X.1991.tb01160.x

    Articles: DFG German National Licenses
  5. 5
    Breuer, D. ; Spohn, T.

    [s.l.] : Nature Publishing Group
    Published 1995
    Staff View
    ISSN:
    1476-4687
    Source:
    Nature Archives 1869 - 2009
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Notes:
    [Auszug] Recent calculations suggest that the spinel-perovskite phase transition at 670 km depth, the boundary between the upper and lower mantles, may play a crucial role in the dynamics of the mantle11'12. The phase boundary appears to stabilize two-layer convection at high Rayleigh numbers, whereas at ...
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1038/378608a0

    Articles: DFG German National Licenses
  6. 6
    Hort, M. ; Spohn, T.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0012-821X
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Geosciences
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://linkinghub.elsevier.com/retrieve/pii/0012-821X(91)90093-W

    Articles: DFG German National Licenses
  7. 7
    Segatz, M. ; Spohn, T. ; Ross, M.N. ; Schubert, G.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0019-1035
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1016/0019-1035(88)90001-2

    Articles: DFG German National Licenses
  8. 8
    Fischer, H.-J. ; Spohn, T.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0019-1035
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1016/0019-1035(90)90005-T

    Articles: DFG German National Licenses
  9. 9
    Spohn, T.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0019-1035
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1016/0019-1035(91)90103-Z

    Articles: DFG German National Licenses
  10. 10
    Stevenson, D.J. ; Spohn, T. ; Schubert, G.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0019-1035
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1016/0019-1035(83)90241-5

    Articles: DFG German National Licenses
  11. 11
    Ross, M.N. ; Schubert, G. ; Spohn, T. ; Gaskell, R.W.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0019-1035
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1016/0019-1035(90)90119-T

    Articles: DFG German National Licenses
  12. 12
    Spohn, T. ; Benkhoff, J.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0019-1035
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1016/0019-1035(90)90139-Z

    Articles: DFG German National Licenses
  13. 13
    Breuer, D. ; Spohn, T. ; Wullner, U.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0032-0633
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Geosciences
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://linkinghub.elsevier.com/retrieve/pii/0032-0633(93)90022-T

    Articles: DFG German National Licenses
  14. 14
    Staff View
    ISSN:
    0273-1177
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://linkinghub.elsevier.com/retrieve/pii/0273-1177(89)90249-4

    Articles: DFG German National Licenses
  15. 15
    Spohn, T. ; Benkhoff, J. ; Klinger, J. ; Grun, E. ; Kochan, H.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0273-1177
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://linkinghub.elsevier.com/retrieve/pii/0273-1177(89)90251-2

    Articles: DFG German National Licenses
  16. 16
    Staff View
    ISSN:
    0273-1177
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://linkinghub.elsevier.com/retrieve/pii/0273-1177(89)90252-4

    Articles: DFG German National Licenses
  17. 17
    Spohn, T.
    Springer
    Published 1981
    Staff View
    ISSN:
    1437-3262
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Geosciences
    Description / Table of Contents:
    Zusammenfassung Schererwärmung bis zum partiellen Aufschmelzen der subduzierten Kruste wird vielfach als Ursache des orogenen Vulkanismus genannt. Eine sorgfältige Betrachtung eines einfachen Schererwämungsmodells führt zu folgenden Resultaten: Schererwärmung unter Vorgabe konstanter Dehnungsrate in der Scherzone führt zu allmählicher Erwärmung, wobei die Temperatur unter der Solidusgrenze bleibt, sofern man vernünftige Werte der Modellparameter wählt. Die Temperaturerhöhung bleibt in diesem Fall beschränkt durch die Rückkopplung von Temperatur und Viskosität. Schererwärmungsinstabilitäten, die zu partiellem Aufschmelzen führen, sind möglich, sofern bei nicht-stationärer Schererwärmung die Scherspannung oder die Dehnungsrate gewisse kritische Werte übersteigen. Es wird gezeigt, daß die Annahme superkritischer und konstanter Scherspannung entlang von 1–10 km langen Wegstücken der subduzierten Kruste mit Beobachtungen und Modellrechnungen verträglich ist. In diesem Fall können Scherinstabilitäten in einer Tiefe von 100 km bis 200 km in der subduzierten Kruste auftreten.
    Abstract:
    Résumé On croit couramment que l'explication du volcanisme orogénique se trouve dans l'échauffement causé pai les tensions d'arrachement et dans la fusion partielle consécutive de la fraction crustale de la lithosphere en voie de subduction. Une considération soigneuse d'un modèle simple d'échauffement par tensions conduit aux résultats suivants: un échauffement sous de telles tensions et dans des conditions avantageuses d'un degré d'extension constant dans la zone de cisaillement conduit à un échauffement par broyage où la température reste maintenue en-dessous de la limite du solidus pour autant qu'on choisisse des valeurs raisonables pour les paramètres du modèle. L'élévation de température reste dans ce cas limitée par le couple température-viscosité. Les instabilités par échauffement sous tension qui conduisent à la mise en fusion partielle, sont possibles pour autant que, sous un échauffement non stationnaire, le cisaillement ou le degré d'extension ne dépasse pas certaines valeurs critiques. On montre que l'adoption d'une tension de cisaillement supercritique et constante le long de tronçons de 1–10 km de la croûte en voie de subduction est compatible avec les observations et avec les calculs déduits du modèle. Dans ce cas des instabilités sous l'effet du cisaillement peuvent se produire dans la croûte en voie de subduction à une profondeur de 100 à 200 km.
    Notes:
    Abstract It is widely believed that the explanation of orogenic volcanism lies in the shear heating and subsequent partial melting of the crustal fraction of subducted lithosphere. Careful examination of simple models of the shear-heating process indicates, however, that this process cannot occur in a system with constant strain-rate boundary conditions, for reasonable values of the strain rate and material parameters. Thermal runaway cannot occur because viscous dissipation process is limited by the effect of temperature on viscosity, although shear-heating instability may develop during non-steady-state shear at stress or strain-rate values above certain critical values. Examination of subduction history models indicates that supercritical shear stresses constant over some tens of kilometers may be found in subduction shear zones. Since instability may develop if such conditions are present over even a 1–10 km range, it is still possible that non-steady-state process could explain the origin of orogenic volcanism.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF01764319

    Articles: DFG German National Licenses
  18. 18
    Blount, A. M. ; Spohn, T.
    Springer
    Published 1982
    Staff View
    ISSN:
    1432-1866
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Geosciences
    Notes:
    Abstract The residual soil overlying a talc deposit, which occurs as a lens between gneiss and serpentinite in Lancaster County, Pennsylvania, contains talc in all size fractions studied (10 μm to less than 2 μm) and in unfractionated samples. A study of soil samples, obtained by auger drilling, indicates that small amounts of talc can be detected by X-ray diffraction in samples obtained over a large area when the X-ray samples are prepared so that the clays are well oriented. Randomly oriented X-ray samples, in which the level of detection of talc is much poorer, also were successfully used to determine the presence of the talc body by means of quantitative measurements. In addition, the latter procedure was found to be superior in determining the actual size and location of the ore body. It is proposed that such procedures might be used in exploration for similar talc deposits.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00206373

    Articles: DFG German National Licenses
  19. 19
    Ziethe, R. ; Breuer, D. ; Spohn, T.
    Springer
    Published 2000
    Staff View
    ISSN:
    1610-2924
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Geosciences
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/s10069-999-1003-5

    Articles: DFG German National Licenses