1932

Abstract

The thermal conductivity of iron alloys at high pressures and temperatures is a critical parameter in governing () the present-day heat flow out of Earth's core, () the inferred age of Earth's inner core, and () the thermal evolution of Earth's core and lowermost mantle. It is, however, one of the least well-constrained important geophysical parameters, with current estimates for end-member iron under core-mantle boundary conditions varying by about a factor of 6. Here, the current state of calculations, measurements, and inferences that constrain thermal conductivity at core conditions are reviewed. The applicability of the Wiedemann-Franz law, commonly used to convert electrical resistivity data to thermal conductivity data, is probed: Here, whether the constant of proportionality, the Lorenz number, is constant at extreme conditions is of vital importance. Electron-electron inelastic scattering and increases in Fermi-liquid-like behavior may cause uncertainties in thermal conductivities derived from both first-principles-associated calculations and electrical conductivity measurements. Additional uncertainties include the role of alloying constituents and local magnetic moments of iron in modulating the thermal conductivity. Thus, uncertainties in thermal conductivity remain pervasive, and hence a broad range of core heat flows and inner core ages appear to remain plausible.

Loading

Article metrics loading...

/content/journals/10.1146/annurev-earth-082517-010154
2018-05-30
2024-06-23
Loading full text...

Full text loading...

/deliver/fulltext/earth/46/1/annurev-earth-082517-010154.html?itemId=/content/journals/10.1146/annurev-earth-082517-010154&mimeType=html&fmt=ahah

Literature Cited

  1. Andrault D, Monteux J, Le Bars M, Samuel M 2016. The deep Earth may not be cooling down. Earth Planet. Sci. Lett. 443:195–203
    [Google Scholar]
  2. Anzellini S, Dewaele A, Mezouar M, Loubeyre P, Morard G 2013. Melting of iron at Earth's inner core boundary based on fast X-ray diffraction. Science 340:464–66
    [Google Scholar]
  3. Aurnou J, Andreadis S, Zhu L, Olson P 2003. Experiments on convection in Earth's core tangent cylinder. Earth Planet. Sci. Lett. 212:119–34
    [Google Scholar]
  4. Badro J, Siebert J, Nimmo F 2016. An early geodynamo driven by exsolution of mantle components from Earth's core. Nature 536:326–28
    [Google Scholar]
  5. Beutl M, Pottlacher G, Jager H 1994. Thermophysical properties of liquid iron. Int. J. Thermophys. 15:1323–31
    [Google Scholar]
  6. Bi Y, Tan H, Jing F 2002. Electrical conductivity of iron under shock compression up to 200 GPa. J. Phys. Condens. Matter 14:10849–55
    [Google Scholar]
  7. Biggin AJ, Piispa EJ, Pesonen LJ, Holme R, Paterson GA et al. 2015. Palaeomagnetic field intensity variations suggest Mesoproterozoic inner-core nucleation. Nature 526:245–48
    [Google Scholar]
  8. Boehler R 1993. Temperatures in the Earth's core from melting point measurements of iron at high static pressures. Nature 363:534–36
    [Google Scholar]
  9. Buffett BA 2000. Earth's core and the geodynamo. Science 288:2007–12
    [Google Scholar]
  10. Buffett BA 2002. Estimates of heat flow in the deep mantle based on the power requirements of the geodynamo. Geophys. Res. Lett. 29: https://doi.org/10.1029/2001GL014649
    [Crossref] [Google Scholar]
  11. Buffett BA, Huppert HE, Lister JR, Woods AW 1996. On the thermal evolution of the Earth's core. J. Geophys. Res. 101:7989–8006
    [Google Scholar]
  12. Davies CJ 2015. Cooling history of Earth's core with high thermal conductivity. Phys. Earth Planet. Inter. 247:65–79
    [Google Scholar]
  13. Davies CJ, Pozzo M, Gubbins D, Alfe D 2015. Constraints from material properties on the dynamics and evolution of Earth's core. Nat. Geosci. 8:678–85
    [Google Scholar]
  14. Davies JH 2013. Global map of solid Earth surface heat flow. Geochem. Geophys. Geosyst. 14:4608–22
    [Google Scholar]
  15. de Koker N, Steinle-Neumann G, Vicek V 2012. Electrical resistivity and thermal conductivity of liquid Fe alloys at high P and T, and heat flux in Earth's core. PNAS 109:4070–73
    [Google Scholar]
  16. Deng L, Seagle S, Fei Y, Shahar A 2013. High pressure and temperature electrical resistivity of iron and implications for planetary cores. Geophys. Res. Lett. 40:33–37
    [Google Scholar]
  17. Drchal V, Kudrnovsky J, Wagenknecht D, Turek I, Khmelevskyi S 2017. Transport properties of iron at the Earth's core conditions: the effect of spin disorder. Phys. Rev. B 96:024432
    [Google Scholar]
  18. Fulkerson W, Moore JP, McElroy DL 1966. Comparison of the thermal conductivity, electrical resistivity, and Seebeck coefficient of a high-purity iron and an Armco iron to 1000°C. J. Appl. Phys. 37:2639–53
    [Google Scholar]
  19. Furlong KP, Chapman DS 2013. Heat flow, heat generation, and the thermal state of the lithosphere. Annu. Rev. Earth Planet. Sci. 41:385–410
    [Google Scholar]
  20. Gomi H, Hirose K 2015. Electrical resistivity and thermal conductivity of hcp Fe-Ni alloys under high pressure: implications for thermal convection in the Earth's core. Phys. Earth Planet. Inter. 247:2–10
    [Google Scholar]
  21. Gomi H, Hirose K, Akai H, Fei Y 2016. Electrical resistivity of substitutionally disordered hcp Fe-Si and Fe-Ni alloys: chemically-induced resistivity saturation in the Earth's core. Earth Planet. Sci. Lett. 451:51–61
    [Google Scholar]
  22. Gomi H, Ohta K, Hirose K, Labrosse S, Caracas R et al. 2013. The high conductivity of iron and thermal evolution of the Earth's core. Phys. Earth Planet. Inter. 224:88–103
    [Google Scholar]
  23. Gubbins D, Alfe D, Davies C, Pozzo M 2015. On core convection and the geodynamo: effects of high electrical and thermal conductivity. Phys. Earth Planet. Inter. 247:56–64
    [Google Scholar]
  24. Gunnarsson O, Calandra M, Han JE 2003. Colloquium: saturation of electrical resistivity. Rev. Mod. Phys. 75:1085–99
    [Google Scholar]
  25. Gurvitch M 1981. Ioffe-Regel criterion and resistivity of metals. Phys. Rev. B 24:7404–7
    [Google Scholar]
  26. Hausoel A, Karolak M, Sasioglu E, Lichtenstein A, Held K et al. 2017. Local magnetic moments in iron and nickel at ambient and Earth's core conditions. Nat. Commun. 8:16062
    [Google Scholar]
  27. Hirose K, Morard G, Sinmyo R, Umemoto K, Hernlund J et al. 2017. Crystallization of silicon dioxide and compositional evolution of the Earth's core. Nature 543:99–102
    [Google Scholar]
  28. Ioffe AF, Regel AR 1960. Non-crystalline, amorphous and liquid electronic semiconductors. Prog. Semicond. 4:237–81
    [Google Scholar]
  29. Jaccard D, Holmes A, Behr G, Inada Y, Onuki Y 2002. Superconductivity of ε-Fe: complete resistive transition. Phys. Lett. A 299:282–86
    [Google Scholar]
  30. Keeler R, Mitchell A 1969. Electrical conductivity, demagnetization and the high-pressure phase transition in shock-compressed iron. Solid State Commun 7:271–74
    [Google Scholar]
  31. Klemens PG, Williams RK 1986. Thermal conductivity of metals and alloys. Int. Metals Rev. 31:197–215
    [Google Scholar]
  32. Konôpková Z, McWilliams RS, Gomez-Perez N, Goncharov AF 2016. Direct measurement of thermal conductivity in solid iron at planetary core conditions. Nature 534:99–101
    [Google Scholar]
  33. Labrosse S 2003. Thermal and magnetic evolution of the Earth's core. Phys. Earth Planet. Inter. 140:127–43
    [Google Scholar]
  34. Labrosse S 2015. Thermal evolution of the core with a high thermal conductivity. Phys. Earth Planet. Inter. 247:36–55
    [Google Scholar]
  35. Labrosse S, Hernlund JW, Coltice N 2007. A crystallizing dense magma ocean at the base of Earth's mantle. Nature 450:866–69
    [Google Scholar]
  36. Labrosse S, Poirier JP, Le Mouel JL 2001. The age of the inner core. Earth Planet. Sci. Lett. 190:111–23
    [Google Scholar]
  37. Lay T, Hernlund J, Buffett BA 2008. Core-mantle boundary heat flow. Nat. Geosci. 1:25–32
    [Google Scholar]
  38. Matassov G 1977. The electrical conductivity of iron-silicon alloys at high pressures and the Earth's core PhD Thesis Lawrence Livermore Lab., Univ California:
    [Google Scholar]
  39. McDonough WF, Sun SS 1995. The composition of the Earth. Chem. Geol. 120:223–53
    [Google Scholar]
  40. Nakagawa T, Tackley PJ 2013. Implications of high core thermal conductivity on Earth's coupled mantle and core evolution. Geophys. Res. Lett. 40:2652–56
    [Google Scholar]
  41. Nimmo F 2015. Energetics of the core. Treatise on Geophysics 8 Core Dynamics, ed. G Schubert 27–65 Amsterdam: Elsevier, 2nd ed.
    [Google Scholar]
  42. Nishi T, Shibata H, Waseda Y, Ohta H 2003. Thermal conductivities of molten iron, cobalt, and nickel by laser flash method. Metall. Mater. Trans. A 34:2801–7
    [Google Scholar]
  43. Ohta K, Kuwayama Y, Hirose K, Shimizu K, Ohishi Y 2016. Experimental determination of the electrical resistivity of iron at Earth's core conditions. Nature 534:95–98
    [Google Scholar]
  44. Olson P 2013. The new core paradox. Science 342:431–32
    [Google Scholar]
  45. O'Rourke JG, Korenaga J, Stevenson DJ 2017. Thermal evolution of Earth with magnesium precipitation in the core. Earth Planet. Sci. Lett. 458:263–72
    [Google Scholar]
  46. O'Rourke JG, Stevenson DJ 2016. Powering Earth's dynamo with magnesium precipitation from the core. Nature 529:387–89
    [Google Scholar]
  47. Pourovskii LV, Mravlje J, Georges A, Simak SI, Abrikosov IA 2017. Electron-electron scattering and thermal conductivity of ε-iron at Earth's core conditions. New J. Phys. 19:073022
    [Google Scholar]
  48. Pozzo M, Alfe D 2016. Saturation of electrical resistivity of solid iron at Earth's core conditions. SpringerPlus 5:256
    [Google Scholar]
  49. Pozzo M, Davies C, Gubbins D, Alfe D 2012. Thermal and electrical conductivity of iron at Earth's core conditions. Nature 485:355–58
    [Google Scholar]
  50. Pozzo M, Davies C, Gubbins D, Alfe D 2013. Transport properties for liquid silicon-oxygen-iron mixtures at Earth's core conditions. Phys. Rev. B 87:014110
    [Google Scholar]
  51. Pozzo M, Davies C, Gubbins D, Alfe D 2014. Thermal and electrical conductivity of solid iron and iron-silicon mixtures at Earth's core conditions. Earth Planet. Sci. Lett. 393:159–64
    [Google Scholar]
  52. Rainey ESG, Kavner A 2014. Peak scaling method to measure temperatures in the laser-heated diamond anvil cell and application to the thermal conductivity of MgO. J. Geophys. Res. 119:8154–70
    [Google Scholar]
  53. Reichlin RL 1983. Measuring the electrical resistance of metals to 40 GPa in the diamond-anvil cell. Rev. Sci. Instrum. 54:1674–77
    [Google Scholar]
  54. Sakamaki K, Takahashi E, Nakajima Y, Nishihara Y, Funakoshi K et al. 2009. Melting phase relation of FeHx up to 20 GPa: implication for the temperature of the Earth's core. Phys. Earth. Planet. Inter. 174:192–201
    [Google Scholar]
  55. Seagle CT, Cottrell E, Fei Y, Hummer DR, Prakapenka VB 2013. Electrical and thermal transport properties of iron and iron-silicon alloy at high pressure. Geophys. Res. Lett. 40:5377–81
    [Google Scholar]
  56. Secco RA 2017. Thermal conductivity and Seebeck coefficient of Fe and Fe-Si alloys: implications for variable Lorenz number. Phys. Earth Planet. Inter. 265:23–34
    [Google Scholar]
  57. Secco RA, Schloessin HH 1989. The electrical resistivity of solid and liquid Fe at pressure up to 7 GPa. J. Geophys. Res. 94:5887–94
    [Google Scholar]
  58. Sha X, Cohen R 2011. First-principles studies of electrical resistivity of iron under pressure. J. Phys. Condens. Matter 23:075401
    [Google Scholar]
  59. Smirnov AV, Tarduno JA, Kulakov EV, McEnroe SA, Bono RK 2016. Palaeointensity, core thermal conductivity and the unknown age of the inner core. Geophys. J. Int. 205:1190–95
    [Google Scholar]
  60. Stacey FD, Anderson OL 2001. Electrical and thermal conductivities of Fe-Ni-Si alloy under core conditions. Phys. Earth Planet. Inter. 124:153–62
    [Google Scholar]
  61. Stacey FD, Loper DE 2007. A revised estimate of the conductivity of iron alloy at high pressure and implications for the core energy balance. Phys. Earth Planet. Inter. 161:13–18
    [Google Scholar]
  62. Tarduno JA, Cottrell RD, Davis WJ, Nimmo F, Bono RK 2015. A Hadean to Paleoarchean geodynamo recorded by single zircon crystals. Science 349:521–24
    [Google Scholar]
  63. Touloukian YS, Powell RW, Ho CY, Klemens PG 1970. Thermophysical Properties of Matter 1 Thermal Conductivity, Metallic Elements and Alloys, ed. YS Touloukian, CY Ho New York: IFI/Plenum
    [Google Scholar]
  64. Watari K, Hirao K, Toriyama M, Ishizaki K 1999. Effect of grain size on the thermal conductivity of Si3N4. J. Am. Ceram. Soc. 82:777–79
    [Google Scholar]
  65. Williams Q, Hemley RJ 2001. Hydrogen in the deep Earth. Annu. Rev. Earth Planet. Sci. 29:365–418
    [Google Scholar]
  66. Williams Q, Jeanloz R, Bass J, Svendsen B, Ahrens TJ 1987. The melting curve of iron to 250 gigapascals: a constraint on the temperature at Earth's center. Science 236:181–82
    [Google Scholar]
  67. Wu B, Driscoll P, Olson P 2011. A statistical boundary layer model for the mantle D″ region. J. Geophys. Res. 116:B12112
    [Google Scholar]
  68. Ziman JM 1972. Principles of the Theory of Solids Cambridge, UK: Cambridge Univ. Press, 2nd ed.
    [Google Scholar]
/content/journals/10.1146/annurev-earth-082517-010154
Loading
/content/journals/10.1146/annurev-earth-082517-010154
Loading

Data & Media loading...

  • Article Type: Review Article
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error