Organisers

• Hans-Peter Bunge (Ludwig-Maximilians-University, Munich, Germany)
• Renata Wentzcovitch (University of Minnesota, Minneapolis, USA)
• Lapo Boschi (Institut für Geophysik, ETH Zurich, Switzerland)

Supports

   CECAM

Description

Earth forming materials are primarily rocks, i.e., aggregates of silicates and oxides, iron alloys, and their melts. Individual phases are complex solid solutions with several components [21], including strongly correlated iron oxides that undergo spin crossovers under pressure [20]. To make contact with seismology, geodynamics, and experiments, mineral properties must be investigated in a wide range of pressures, temperatures, and chemical compositions. The complexity of these materials and conditions, in addition to the well known difficulties typical of predictive materials simulations, poses great challenges and new opportunities to materials computations.
Topics illustrating the need for computational studies of minerals include: global and local seismic observations such as the current view of Earth’s structure [5, 6], the D” region [3, 30] and core [22, 29], attenuation [31,32] and anisotropy [33] in seismic wave propagation, thermochemical convection [9, 27], including whole mantle convection and plate subduction, mantle viscosity structure [12], etc. The recent discovery of terrestrial exoplanets has been pushing the frontiers of high pressure studies to the multi-Mbar and to the 10 eV temperature range [34]. Simulations of these planetary interiors using new mineral physics results in this PT range will also be discussed [35]. From the experimental and computational view points the main issues that will be addressed are: elasticity [36], thermodynamics and phase equilibrium in single and multi-phase aggregates [21], heat transport [38], ionic diffusion [38], plasticity [28], and melts [25].

References

1) Earth’s Deep Interior, Geophysical Monograph Series, vol. 117, Eds. Karato S, Liebermann, R., Masters, G., Stixrude, L., American Geophysical Union (2000).
2) Deep Mantle: Structure, Composition, and Evolution, Geophysical Monograph Series, vol. 160, Eds. Van Der Hilst, R. D., Bass, J. D., Matas, J., Trampert, J., American Geophyscial Union, Washington, DC (2005).
3) The Last Phase Transition, Geophysical Monograph Series, vol. 174, Eds. Hirose, K., Brodholt, J., Lay, T., and Yuen. D., American Geophyscial Union, Washington, DC (2007).
4) Wentzcovitch, R. M., Martins, J. L., and Price, G. D., Ab initio molecular dynamics with variable cell shape: application to MgSiO3, Phys. Rev. Lett., 70, 3947 (1993).
5) Masters, G., Laske, G., Bolton, H., and Dziewonski, A. The relative behavior of shear velocity, bulk sound velocity, and compressional velocity in the mantle: Implications for chemical and thermal structure. In: Karato S et al. (eds) Earth’s Deep Interior. American Geophysical Union Monograph 117, pp 63 (2000).
6) Hirose, K. and Lay, T., Discovery of post-perovskite and new views on the oremantle boundary region, Elements 4, 183 (2008).
7) Bunge, H. P., Ricard, Y, Matas, J., Non-adiabaticity in mantle convection, Geophys. Res. Lett. 28 (2001).
8) Schuberth, B. S. A., Bunge, H. P., Steinle-Neumann, G., et al., Thermal versus elastic heterogeneity in high-resolution mantle circulation models with pyrolite composition: High plume excess temperatures in the lowermost mantle Geochem., Geophys., Geosyst. 10, Q01W01 (2009).
9) Tackley, P.J., Mantle convection and plate tectonics: Toward an integrated physical and chemical theory, Science 288, 2002 (2000).
10) Labrosse, S., Hernlund, J.W., Coltice, N., A crystallizing dense magma ocean at
the base of the Earth's mantle, Nature 450, 866 (2007).
11) Christensen, U. and Yuen, D. A., Layered convection induced by mineral phasetransitions, J. Geophys. Res. 90 (1985).
12) Simmons, N., Forte A. M., Grand, S. P., Joint seismic, geodynamic and mineral physical constraints on three-dimensional mantle heterogeneity: Implications for the relative importance of thermal versus compositional heterogeneity, Geophys. J. Int. 177, 1284 (2009).
13) Lin, J. F., Karato, S. I., Bass, J. D., et al., Frontiers and grand challenges in mineral physics of the deep mantle, Phys. Earth Planet. Int. (170) 151 (2008).
14) Marquardt, H., Speziale, S., Reichmann, H. J., et al., Shear Anisotropy of ferropericlase in Earth's lower mantle, Science 324, 224 (2009).
15) Bass, J. D., Recent progress in studies of the elastic properties of earth materials Phys. Earth Planet. Int. 170, 207 (2008).
16) Badro, J., Fiquet, G., Guyot, F., et al., Iron partitioning in Earth's mantle: Toward a deep lower mantle discontinuity, Science 300, 789 (2003).
17) Badro, J., Rueff, J. P., Vanko, G., et al., Electronic transitions in perovskite: Possible nonconvecting layers in the lower mantle, Science 305, 383 (2004).
18) Murakami, M., Sinogeikin, S. V., Bass, J. D., Sata, N., Ohishi, Y., and Hirose, K., Sound Velocity of MgSiO3 Post-Perovskite Phase: A Constraint on the D” Discontinuity, Earth Planet. Sci. Lett. 259, 18 (2007).
19) McCammon C., Perovskite as a possible sink for ferric iron in the lower mantle Nature 387, 694 (1997).
20) Wentzcovitch, R. M., Justo, J. F., Wu, Z., da Silva, C. R. S., Yuen, D., and Kohlstedt, D., Anomalous compressibility of ferropericlase throughout the iron spin cross-over, Proc. Natl. Acad. Sc. 106, 8447 (2009).
21) Stixrude, L., and Lithgow-Bertelloni, C., Thermodynamics of mantle minerals - I. Physical properties, Geophys. J. Int. 162, 610 (2005).
22) Alfe, D., Temperature of the inner-core boundary of the Earth: Melting of iron at high pressure from first-principles coexistence simulations, Phys. Rev. B 79, 060101 (2009).
23) Hammonds, K. D., Dove., M. T., Giddy, A. P., et al., Rigid-unit phonon modes and structural phase transitions in framework silicates, Amer. Mineral. 81, 1057, (1996).
24) Stixrude, L, de Koker, N., Sun, N., e Mookherjee, M., and Karki, B. B., Thermodynamics of silicate liquids in the deep Earth, Earth Planet. Sc. Lett. 278, 226 (2009).
25) Vinograd V. L., Sluiter, M. H. F., Winkler, B., Subsolidus phase relations in the CaCO3-MgCO3 system predicted from the excess enthalpies of supercell structures with single and double defects, Phys. Rev. B 79, 104201 (2009).
26) Piazzoni, A., Steinle-Neumann, G., Bunge, H., and Dolejs, D., A mineralogical model for density and elasticity of the Earth's mantle, Geochem. Geophys. Geosyst. 8, Q11010 (2007).
27) Metsue, A., Carrez, P., Mainprice, D., and Cordier, P., Numerical modelling of dislocations and deformation mechanisms in CaIrO3 and MgGeO3 post5 perovskites-Comparison with MgSiO3 post-perovskite, Phys. Earth Planet. Int. 174, 165 (2009).
28) Gerya, T. V., Connolly, J. A. D., Rocks generated under extreme pressure and temperature conditions: Mechanisms, concepts, models, Gerya, T. V., Connolly, J. A. D., Lithos 103, VII-VIII (2008).
29) Labrosse, S., Poirier, J. P, Le Mouel, J. L., The age of the inner core, Earth Planet. Sc. Lett. 190, 111 (2001).
30) Wentzcovitch, R., Tsuchiya, T., Tsuchiya, J., Umemoto, K., Thermodynamic properties and stability of MgSiO3 post-perovskite, Chapter 08 in Post-Perovskite: The Last Phase Transition, Geophysical Monograph Series, vol. 174 (K. Hirose, J. Brodholt, T. Lay, and D. Yuen, eds.). American Geophysical Union, Washington, DC (2007).
31) Lekic, V., Matas, J., Panning, M., et al., Measurement and implications of frequency dependence of attenuation. Earth Planet Sc. Lett. 282, 285 (2009).
32) Dalton, C. A., Ekstrom, G., Dziewonski A. M., Global seismological shear velocity and attenuation: A comparison with experimental observations, Earth Planet. Sc. Lett. 284, 65 (2009).
33) Kustowski, B., Ekstrom, G., Dziewonski, A. M., Anisotropic shear-wave velocity structure of the Earth's mantle: A global model, J. Geophys. Res. 113, B06306 (2008).
34) Umemoto, K., Wentzcovitch, R., and Allen, P. B., Dissociation of MgSiO3 in the Cores of Gas Giants and Terrestrial Exoplanets, Science, 311, 983 (2006).
35) Van den Berg, A., et al., Internal dynamics and thermal evolution of super-Earths with post-perovskite dissociation, Phys. Earth Planet. Int., in press (2009).
36) Wentzcovitch, R. M., Karki, B. B., Cococcioni, M., and de Gironcoli, S., Thermoelastic properties of of MgSiO3-perovskite: insights on the nature of the Earth’s lower mantle, Phys. Rev. Lett. 92, 018501 (2004).
37) Stackhouse, S., Stixrude, L., Thermal conductivity of MgO and MgSiO3 perovskite at lower mantle conditions, Phys. Earth Planet. Int., in press (2009).
38) Karki, B. B. and Khanduja, G., A computational study of ionic vacancies and diffusion in MgSiO3 perovskite and post-perovskite, Earth Planet. Sc. Lett. 260 (2007).