Space Science Reviews

, Volume 155, Issue 1–4, pp 293–335 | Cite as

Polarity Reversals from Paleomagnetic Observations and Numerical Dynamo Simulations

  • Hagay Amit
  • Roman Leonhardt
  • Johannes Wicht


Recent advances in the study of geomagnetic field reversals are reviewed. These include studies of the transitional field during the last geomagnetic reversal and the last geomagnetic excursion based on paleomagnetic observations, and analysis of reversals in self-consistent 3D numerical dynamo simulations. Field models inferred from observations estimate reversal duration in the range of 1–10 kyr (depending on site location). The transitional fields during both the Matuyama/Brunhes reversal and the Laschamp excursion are characterized by low-latitude reversed flux formation and subsequent poleward migration. During both events the dipole as well as the non-dipole field energies decrease. However, while the non-dipole energy dominates the dipole energy for a period of 2 kyr in the reversal, the non-dipole energy merely exceeds the dipole energy for a very brief period during the excursion. Numerical dynamo simulations show that stronger convection, slower rotation, and lower electrical conductivity provide more favorable conditions for reversals. A non-dimensional number that depends on the typical length scale of the flow and represents the relative importance of inertial effects, termed the local Rossby number, seems to determine whether a dynamo will reverse or not. Stable polarity periods in numerical dynamos may last about 1 Myr, whereas reversals may last about 10 kyr. Numerical dynamo reversals often involve prolonged dipole collapse followed by shorter directional instability of the dipole axis, with advective processes governing the field variation. Magnetic upwellings from the equatorial inner-core boundary that produce reversed flux patches at low-latitudes of the core-mantle boundary could be significant in triggering reversals. Inferences from the observational and modeling sides are compared. We summarize with an outlook on some open questions and future prospects.


Geomagnetic field Paleomagnetic reconstruction Geodynamo Reversal Excursion Magnetic dipole Virtual geomagnetic pole 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. L. Alldredge, Harmonics required in main field and secular variation models. J. Geomagn. Geoelectr. 36, 63–72 (1984) Google Scholar
  2. H. Amit, P. Olson, Geomagnetic dipole tilt changes induced by core flow. Phys. Earth Planet. Inter. 166, 226–238 (2008) ADSCrossRefGoogle Scholar
  3. H. Amit, P. Olson, A dynamo cascade interpretation of the geomagnetic dipole decrease. Geophys. J. Int. 181, 1411–1427 (2010) ADSGoogle Scholar
  4. H. Amit, J. Aubert, G. Hulot, P. Olson, A simple model for mantle-driven flow at the top of Earth’s core. Earth Planets Space 60, 845–854 (2008) ADSGoogle Scholar
  5. J. Aubert, H. Amit, G. Hulot, Detecting thermal boundary control in surface flows from numerical dynamos. Phys. Earth Planet. Inter. 160, 143–156 (2007) ADSCrossRefGoogle Scholar
  6. J. Aubert, H. Amit, G. Hulot, P. Olson, Thermo-chemical wind flows couple Earth’s inner core growth to mantle heterogeneity. Nature 454, 758–761 (2008a) ADSCrossRefGoogle Scholar
  7. J. Aubert, J. Aurnou, J. Wicht, The magnetic structure of convection-driven numerical dynamos. Geophys. J. Int. 172, 945–956 (2008b) ADSCrossRefGoogle Scholar
  8. J. Aubert, S. Labrosse, C. Poitou, Modelling the paleo-evolution of the geodynamo. Geophys. J. Int. 179, 1414–1428 (2009) ADSCrossRefGoogle Scholar
  9. J. Aurnou, S. Andreadis, L. Zhu, P. Olson, Experiments on convection in Earth’s core tangent cylinder. Earth Planet. Sci. Lett. 212, 119–134 (2003) ADSCrossRefGoogle Scholar
  10. S. Baumgartner, J. Beer, J. Masarik, G. Wagner, L. Meynadier, H.A. Synal, Geomagnetic modulation of the 36cl flux in the grip ice core, greenland. Science 279(5355), 1330–1332 (1998) ADSCrossRefGoogle Scholar
  11. M. Berhanu, R. Monchaux, S. Fauve, N. Mordant, F. Petrelis, A. Chiffaudel, F. Daviaud, B. Dubrulle, L. Marie, F. Ravelet, M. Bourgoin, P. Odier, J.-F. Pinton, R. Volk, Magnetic fld reversals in an experimental turbulent dynamo. Europhys. Lett. 77 (2007). doi: 10.1209/0295–5075/77/59001
  12. C.L. Blanchet, N. Thouveny, T. de Garidel-Thoron, Evidence for multiple paleomagnetic intensity lows between 30 and 50 ka bp from a western equatorial pacific sedimentary sequence. Quat. Sci. Rev. 25, 1039–1052 (2006) ADSCrossRefGoogle Scholar
  13. U. Bleil, T.V. Dobeneck, Geomagnetic events and relative paleointensity records; clues to high-resolution paleomagnetic chronostratigraphies of late quaternary marine sediments?, in Use of Proxies in Paleoceanography; Examples from the South Atlantic, ed. by G. Fischer, G. Wefer (Springer, Berlin, 1999), pp. 635–654 Google Scholar
  14. J. Bloxham, The expulsion of magnetic flux from the Earth’s core. Geophys. J. R. Astr. Soc. 87, 669–678 (1986) Google Scholar
  15. J. Bloxham, D. Gubbins, Geomagnetic field analysis—iv. Testing the frozen-flux hypothesis. Geophys. J. R. Astr. Soc. 84, 139–152 (1986) ADSGoogle Scholar
  16. J. Bloxham, A. Jackson, Fluid flow near the surface of the Earth’s outer core. Rev. Geophys. 29, 97–120 (1991) ADSCrossRefGoogle Scholar
  17. N. Bonhommet, J. Babkine, Sur la presence daimentations inversees dans la chaine des puys. C. R. Acad. Sci. Ser. B 264, 92 (1967) Google Scholar
  18. M.B. Brown, R. Holme, A. Bargery, Exploring the influence of the non-dipole field on magnetic records for field reversals and excursions. Geophys. J. Int. 168, 541–550 (2007) ADSCrossRefGoogle Scholar
  19. B. Brunhes, Recherches sur le direction d’aimantation des roches volcaniques. J. Phys. 5, 705–724 (1906) Google Scholar
  20. F. Busse, R. Simitev, Toroidal flux oscillation as possible cause of geomagnetic excursions and reversals. Phys. Earth Planet. Inter. 168, 237–243 (2008) ADSCrossRefGoogle Scholar
  21. S.C. Cande, D.V. Kent, Revised calibration of the geomagnetic polarity timescale forthe late cretaceous and cenozoic. J. Geophys. Res. 100, 6093–6095 (1995) ADSCrossRefGoogle Scholar
  22. W.S. Cassata, B.S. Singer, J. Cassidy, Laschamp and mono lake geomagnetic excursions recorded in new zealand. Earth Planet. Sci. Lett. 268, 76–88 (2008) ADSCrossRefGoogle Scholar
  23. J.E.T. Channell, Late brunhes polarity excursions (mono lake, laschamp, iceland basin and pringle falls) recorded at odp site 919 (Irminger basin). Earth Planet. Sci. Lett. 244, 378–393 (2006) ADSCrossRefGoogle Scholar
  24. U. Christensen, J. Aubert, Scaling properties of convection-driven dynamos in rotating spherical shells and application to planetary magnetic fields. Geophys. J. Int. 166, 97–114 (2006) ADSCrossRefGoogle Scholar
  25. U. Christensen, P. Olson, Secular variation in numerical geodynamo models with lateral variations of boundary heat flow. Phys. Earth Planet. Inter. 138, 39–54 (2003) ADSCrossRefGoogle Scholar
  26. U. Christensen, J. Wicht, Numerical dynamo simulations, in Treatise on Geophysics, ed. by P. Olson, vol. 8 (Elsevier, Amsterdam, 2007) Google Scholar
  27. U. Christensen, P. Olson, G. Glatzmaier, Numerical modelling of the geodynamo: a systematic parameter study. Geophys. J. Int. 138, 393–409 (1999) ADSCrossRefGoogle Scholar
  28. A. Chulliat, N. Olsen, Observation of magnetic diffusion in the Earth’s outer core from Magsat, Ørsted and CHAMP data. J. Geophys. Res. 115, B05105 (2010). doi: 10.1029/2009JB006994 CrossRefGoogle Scholar
  29. B.M. Clement, Geographical distribution of transitional VGPs: evidence for non-zonal symmetry during the matuyama-brunhes geomagnetic reversal. Earth Planet. Sci. Lett. 104, 48–58 (1991) ADSCrossRefGoogle Scholar
  30. B.M. Clement, Dependence of the duration of geomagnetic polarity reversals on site latitude. Nature 428, 637–640 (2004) ADSCrossRefGoogle Scholar
  31. B.M. Clement, D.V. Kent, A southern hemisphere record of the matuyama-brunhes polarity reversal. Geophys. Res. Lett. 18, 81–84 (1991) ADSCrossRefGoogle Scholar
  32. R. Coe, G. Glatzmaier, Symmetry and stability of the geomagnetic field. Geophys. Res. Lett. 33, L21311 (2006) ADSCrossRefGoogle Scholar
  33. R.S. Coe, L. Hongre, G.A. Glatzmaier, An examination of simulated geomagnetic reversals from a palaeomagnetic perspective. Philos. Trans. R. Soc. Lond. 358, 1141–1170 (2000) ADSCrossRefGoogle Scholar
  34. A. Cox, Reversed flux as reversal mechanism. Rev. Geophys. Space Phys. 13, 35–51 (1975) ADSCrossRefGoogle Scholar
  35. A. Cox, J. Hillhouse, M. Fuller, Paleomagnetic records of polarity transitions, excursions, and secular variation. Rev. Geophys. Space Phys. 13, 185–189 (1975) CrossRefGoogle Scholar
  36. P. Davidson, An Introduction to Magnetohydrodynamics (Cambridge University Press, Cambridge, 2001) zbMATHCrossRefGoogle Scholar
  37. E. Dormy, J.-P. Valet, V. Courtillot, Numerical models of the geodynamo and observational constraints. Geochem. Geophys. Geosyst. 1(10), 1037 (2000). doi: 10.1029/2000GC000062 CrossRefGoogle Scholar
  38. P. Driscoll, P. Olson, Polarity reversals in geodynamo models with core evolution. Earth Planet. Sci. Lett. 282, 24–33 (2009) ADSCrossRefGoogle Scholar
  39. G. Glatzmaier, Numerical simulation of stellar convective dynamos. 1: The model and method. J. Comp. Phys. 55, 461–484 (1984) ADSCrossRefGoogle Scholar
  40. G. Glatzmaier, Dynamo models: how realistic are they? Annu. Rev. Earth Planet. Sci. 30, 237–257 (2002) ADSCrossRefGoogle Scholar
  41. G. Glatzmaier, P. Roberts, A three-dimensional convective dynamo solution with rotating and finitely conducting inner core and mantle. Phys. Earth Planet. Inter. 91, 63–75 (1995a) CrossRefGoogle Scholar
  42. G. Glatzmaier, P. Roberts, A three-dimensional self-consistent computer simulation of a geomagnetic field reversal. Nature 377, 203–209 (1995b) ADSCrossRefGoogle Scholar
  43. G. Glatzmaier, P. Roberts, Simulating the geodynamo. Comput. Phys. 38, 269–288 (1997) Google Scholar
  44. G. Glatzmaier, R. Coe, L. Hongre, P. Roberts, The role of the earth’s mantle in controlling the frequency of geomagnetic reversals. Nature 401, 885–890 (1999) ADSCrossRefGoogle Scholar
  45. D. Gubbins, Mechanism for geomagnetic polarity reversals. Nature 326, 167–169 (1987) ADSCrossRefGoogle Scholar
  46. D. Gubbins, The distinction between geomagnetic excursions and reversals. Geophys. J. Int. 137, F1–F3 (1999) CrossRefGoogle Scholar
  47. D. Gubbins, A. Jones, C. Finlay, Fall in Earth’s magnetic field is erratic. Science 312, 900–902 (2006) ADSCrossRefGoogle Scholar
  48. D. Gubbins, P. Willis, B. Sreenivasan, Correlation of Earth’s magnetic field with lower mantle thermal and seismic structure. Phys. Earth Planet. Inter. 162, 256–260 (2007) ADSCrossRefGoogle Scholar
  49. H. Guillou, B.S. Singer, C. Laj, C. Kissel, S. Scailleta, B.R. Jicha, On the age of the laschamp geomagnetic excursion. Earth Planet. Sci. Lett. 227, 331–341 (2004) ADSCrossRefGoogle Scholar
  50. Y. Guyodo, J.-P. Valet, Global changes in intensity of the earth’s field during the past 800 kyr. Nature 399, 249–252 (1999) ADSCrossRefGoogle Scholar
  51. F. Heller, Self-reversal of natural remanent magnetisation in the olby-laschamp lavas. Nature 284(5754), 334–335 (1980) ADSCrossRefGoogle Scholar
  52. K.A. Hoffman, Palaeomagnetic excursions, aborted reversals and transitional fields. Nature 294, 67–69 (1981) ADSCrossRefGoogle Scholar
  53. K.A. Hoffman, Dipolar reversal states of the geomagnetic field and core mantle dynamics. Nature 359, 789–794 (1992) ADSCrossRefGoogle Scholar
  54. K.A. Hoffman, Transitional paleomagnetic field behavior: Preferred paths or patches? Surv. Geophys. 17, 207–211 (1996) ADSCrossRefGoogle Scholar
  55. K. Hori, J. Wicht, U. Christensen, The effect of thermal boundary conditions on dynamos driven by internal heating. Phys. Earth Planet. Inter. (2010). doi: 10.1016/j.pepi.2010.06.011 zbMATHGoogle Scholar
  56. G. Hulot, F. Lhuillier, J. Aubert, Earth’s dynamo limit of predictability. Geophys. Res. Let. 37, L06305 (2010). doi: 10.1029/2009GL041869 CrossRefGoogle Scholar
  57. M. Hyodo, Possibility of reconstruction of the past geomagnetic field from homogeneous sediments. J. Geomagn. Geoelectr. 36, 45–62 (1984) Google Scholar
  58. M. Ingham, G. Turner, Behaviour of the geomagnetic field during the matuyama-brunhes polarity transition. Phys. Earth Planet. Inter. 168, 163–178 (2008) ADSCrossRefGoogle Scholar
  59. A. Jackson, A. Jonkers, M. Walker, Four centuries of geomagnetic secular variation from historical records. Philos. Trans. R. Soc. Lond. A358, 957–990 (2000) ADSGoogle Scholar
  60. D. Jault, Axial invariance of rapidly varying diffusionless motions in the Earth’s core interior. Phys. Earth Planet. Inter. 166, 67–76 (2008) ADSGoogle Scholar
  61. A. Jonkers, Long-range dependence in the cenozoic reversal record. Phys. Earth Planet. Inter. 135, 253–266 (2003) ADSCrossRefGoogle Scholar
  62. C. Kissel, C. Laj, L. Labeyrie, T. Dokken, A. Voelker, D. Blamart, Rapid climatic variations during marine isotope stage 3: magnetic analyses of sediments from Nordic seas and north Atlantic. Earth Planet. Sci. Lett. 171, 489–502 (1999) ADSCrossRefGoogle Scholar
  63. M.F. Knudsen, P.M. Holm, N. Abrahamsen, Paleomagnetic results from a reconnaissance study of Santiago (cape verde islands): Identification of cryptochron c2r.2r-1. Phys. Earth Planet. Inter. 173, 279–289 (2009) ADSCrossRefGoogle Scholar
  64. M. Korte, C. Constable, Continuous geomagnetic field models for the past 7 millennia: 2, cals7k. Geochem. Geophys. Geosyst. 6, Q02H16 (2005). doi: 10.1029/2004GC000801 CrossRefGoogle Scholar
  65. D. Krása, V.P. Shcherbakov, T. Kunzmann, N. Petersen, Self-reversal of remanent magnetization in basalts due to partially oxidized titanomagnetites. Geophys. J. Int. 162, 115–136 (2005) ADSCrossRefGoogle Scholar
  66. C. Kutzner, U. Christensen, Effects of driving mechanisms in geodynamo models. Geophys. Res. Lett. 27, 29–32 (2000) ADSCrossRefGoogle Scholar
  67. C. Kutzner, U. Christensen, From stable dipolar towards reversing numerical dynamos. Phys. Earth Planet. Inter. 131, 29–45 (2002) ADSCrossRefGoogle Scholar
  68. C. Kutzner, U. Christensen, Simulated geomagnetic reversals and preferred virtual geomagnetic pole paths. Geophys. J. Int. 157, 1105–1118 (2004) ADSCrossRefGoogle Scholar
  69. C. Laj, J.E.T. Channell, Geomagnetic excursions, in Treatise in Geophysics, ed. by M. Kono, vol. 5 (Elsevier, Amsterdam, 2007), pp. 373–416 CrossRefGoogle Scholar
  70. C. Laj, A. Mazaud, R. Weeks, M. Fuller, E. Herrero-Bevera, Geomagnetic reversal paths. Nature 351, 447 (1991) ADSCrossRefGoogle Scholar
  71. C. Laj, N. Szeremeta, C. Kissel, H. Guillou, Geomagnetic paleointensities at Hawaii between 3.9 and 2.1 ma: preliminary results. Earth Planet. Sci. Lett. 179, 191–204 (2000) ADSCrossRefGoogle Scholar
  72. C. Laj, C. Kissel, V. Scao, J. Beer, D.M. Thomas, H. Guillou, R. Muscheler, G. Wagner, Geomagnetic intensity and inclination variations at Hawaii for the past 98 kyr from core soh-4: a new study and a comparison with existing contemporary data. Phys. Earth Planet. Inter. 129, 205–243 (2002) ADSCrossRefGoogle Scholar
  73. C. Laj, C. Kissel, A.P. Roberts, Geomagnetic field behavior during the iceland basin and laschamp geomagnetic excursions: a simple transitional field geometry? Geochem. Geophys. Geosyst. 7(3), Q03004 (2006). doi: 10.1029/2005GC001122 CrossRefGoogle Scholar
  74. L. Lanci, C. Kissel, R. Leonhardt, C. Laj, Morphology of the iceland basin excursion from a spherical harmonics analysis and an iterative bayesian inversion procedure of sedimentary records. Phys. Earth Planet. Inter. 169, 131–139 (2008) ADSCrossRefGoogle Scholar
  75. C.G. Langereis, Excursions in geomagnetism. Nature 399, 207–208 (1999) ADSCrossRefGoogle Scholar
  76. C.G. Langereis, A.A.M.V. Hoof, P. Rochette, Longitudinal confinement of geomagnetic reversal paths as a possible sedimentary artifact. Nature 358, 226–230 (1992) ADSCrossRefGoogle Scholar
  77. C.G. Langereis, M.J. Dekkers, G.J. De Lange, M. Paterne, P.J.M. Van Santvoort, Magnetostratigraphy and astronomical calibration of the: Last 1.1 myr from an eastern Mediterranean piston core and dating of short events in the brunhes. Geophys. J. Int. 129(1), 75–94 (1997) ADSCrossRefGoogle Scholar
  78. R. Leonhardt, K. Fabian, Paleomagnetic reconstruction of the global geomagnetic field evolution during the matuyama/brunhes transition: Iterative bayesian inversion and independent verification. Earth Planet. Sci. Lett. 253, 172–195 (2007) ADSCrossRefGoogle Scholar
  79. R. Leonhardt, H.C. Soffel, A reversal of the earth’s magnetic field recorded in midmiocene lava flows of Gran canaria: Paleointensities. J. Geophys. Res. 107(B11), 2299 (2002). doi: 10.1029/2001JB000949 ADSCrossRefGoogle Scholar
  80. R. Leonhardt, K. Fabian, M. Winklhofer, A. Ferk, C. Kissel, C. Laj, Geomagnetic field evolution during the laschamp excursion. Earth Planet. Sci. Lett. 278, 87–95 (2009) ADSCrossRefGoogle Scholar
  81. S. Levi, H. Audunsson, R.A. Duncan, L. Kristjansson, P.-Y. Gillot, S.P. Jakobsson, Late pleistocene geomagnetic excursion in icelandic lavas: confirmation of the laschamp excursion. Earth Planet. Sci. Lett. 96, 443–457 (1990) ADSCrossRefGoogle Scholar
  82. J. Li, T. Sato, A. Kageyama, Repeated and sudden reversals of the dipole field generated by spherical dynamo action. Science 295, 1887–1890 (2002) ADSCrossRefGoogle Scholar
  83. L.E. Lisiecki, M.E. Raymo, A pliocene-pleistocene stack of 57 globally distributed benthic d18o records. Paleoceanography 20, PA1003 (2005). doi: 10.1029/2004PA001071 ADSCrossRefGoogle Scholar
  84. J. Love, Paleomagnetic volcanic data and geometric regularity of reversals and excursions. J. Geophys. Res. 103, 12,435–12,452 (1998) ADSCrossRefGoogle Scholar
  85. J.J. Love, Statistical assessment of preferred transitional vgp longitudes on palaeomagnetic lava data. Geophys. J. Int. 140, 211–221 (2000) ADSCrossRefGoogle Scholar
  86. J.J. Love, A. Mazaud, A database for the matuyama-brunhes magnetic reversal. Phys. Earth Planet. Int. 103, 207–245 (1997) ADSCrossRefGoogle Scholar
  87. S.P. Lund, M. Schwartz, L. Keigwin, T. Johnson, Deep-sea sediment records of the laschamp geomagnetic field excursion (<41,000 calender years before present). J. Geophys. Res. 110, B04101 (2005). doi: 10.1029/2003JB002943 CrossRefGoogle Scholar
  88. G. Masters, G. Laske, H. Bolton, A. Dziewonski, The relative behavior of shear velocity, bulk sound velocity, and compressional velocity in the mantle: implications for chemical and thermal structure, in Earth’s Deep Interior, ed. by S. Karato, A. Forte, R. Liebermann, G. Masters, L. Stixrude. AGU Monograph, vol. 117 (AGU, Washington D.C., 2000) Google Scholar
  89. A. Mazaud, An attempt at reconstructing the geomagnetic field at the core-mantle boundary during the upper Olduvai polarity transition (1.66 myear). Phys. Earth Planet. Inter. 90, 211–219 (1995) ADSCrossRefGoogle Scholar
  90. A. Mazaud, ‘Sawtooth’ variation in magnetic intensity profiles and delayed acquisition of magnetization in deep sea cores. Earth Planet. Sci. Lett. 139, 379–386 (1996) ADSCrossRefGoogle Scholar
  91. A. Mazaud, C. Laj, M. Bender, A geomagnetic chronology for antarctic ice accumulation. Geophys. Res. Lett. 21(5), 337–340 (1994) ADSCrossRefGoogle Scholar
  92. R.T. Merrill, P.L. McFadden, Geomagnetic polarity transitions. Rev. Geophys. 37, 201–226 (1999) ADSCrossRefGoogle Scholar
  93. R. Merrill, M. McElhinny, P. McFadden, The Magnetic Field of the Earth: Paleomagnetism, the Core, and the Deep Mantle (Academic Press, San Diego, 1998) Google Scholar
  94. H. Moffatt, Magnetic Field Generation in Electrically Conducting Fluids (Cambridge University Press, Cambridge, 1978) Google Scholar
  95. F. Nimmo, Energetics of the core, in Treatise on Geophysics, ed. by P. Olson, vol. 8 (Elsevier, Amsterdam, 2007) Google Scholar
  96. N. Nishikawa, K. Kusano, Simulation study of symmetry-breaking instability and the dipole field reversal in a rotating spherical shell dynamo. Phys. Plasmas 15, 082903 (2008) ADSCrossRefGoogle Scholar
  97. N. Olsen, M. Mandea, Rapidly changing flows in the Earth’s core. Nature Geosci. 1, 390–394 (2008) ADSCrossRefGoogle Scholar
  98. P. Olson, Gravitational dynamos and the low frequency geomagnetic secular variation. Proc. Nat. Acad. Sci. 104, 20159–20166 (2007) ADSCrossRefGoogle Scholar
  99. P. Olson, H. Amit, Changes in earth’s dipole. Naturwissenschaften 93, 519–542 (2006) ADSCrossRefGoogle Scholar
  100. P. Olson, U. Christensen, The time averaged magnetic field in numerical dynamos with nonuniform boundary heat flow. Geophys. J. Int. 151, 809–823 (2002) ADSCrossRefGoogle Scholar
  101. P. Olson, U. Christensen, Dipole moment scaling for convection-driven planetary dynamos. Earth Planet. Sci. Lett. 250, 561–571 (2006) ADSCrossRefGoogle Scholar
  102. P. Olson, U. Christensen, G. Glatzmaier, Numerical modeling of the geodynamo: Mechanisms of field generation and equilibration. J. Geophys. Res. 104, 10383–110404 (1999) ADSCrossRefGoogle Scholar
  103. P. Olson, P. Driscoll, H. Amit, Dipole collapse and reversal precursors in a numerical dynamo. Phys. Earth Planet. Inter. 173, 121–140 (2009) ADSCrossRefGoogle Scholar
  104. P. Olson, R. Coe, P. Driscoll, G. Glatzmaier, P. Roberts, Geodynamo reversal frequency and heterogeneous core-mantle boundary heat flow. Phys. Earth Planer. Inter. 180, 66–79 (2010) ADSCrossRefGoogle Scholar
  105. E. Parker, Hydromagnetic dynamo models. Astrophys. J. 121, 293–314 (1955) ADSCrossRefGoogle Scholar
  106. M. Prévot, P. Camps, Absence of preferred longitude sectors for poles from volcanic records of geomagnetic reversals. Nature 366, 53–57 (1993) ADSCrossRefGoogle Scholar
  107. M. Prévot, E.A. Mankinen, R.S. Coe, S. Grommé, The Steens mountain (Oregon) geomagnetic polarity transition 2. field intensity variations and discussion of reversal models. J. Geophys. Res. 90, 10417–10448 (1985) ADSCrossRefGoogle Scholar
  108. A.P. Roberts, Geomagnetic excursions: Knowns and unknowns. Geophys. Res. Lett. 35, L17307 (2008) ADSCrossRefGoogle Scholar
  109. P. Roberts, S. Scott, On analysis of the secular variation, 1, a hydromagnetic constraint: Theory. J. Geomagn. Geoelectr. 17, 137–151 (1965) Google Scholar
  110. A.P. Roberts, M. Winklhofer, Why are geomagnetic excursions not always recorded in sediments? Constraints from post-depositional remanent magnetization lock-in modelling. Earth Planet. Sci. Lett. 227, 345–359 (2004) ADSCrossRefGoogle Scholar
  111. J. Rotvig, An investigation of reversing numerical dynamos driven by either differential or volumetric heating. Phys. Earth Planet. Inter. 176, 69–82 (2009) ADSCrossRefGoogle Scholar
  112. D. Ryan, G. Sarson, Are geomagnetic field reversals controlled by turbulence within the Earth’s core? Geophys. Res. Lett. 34, L02307 (2007). doi: 10.1029/2006GL028291 CrossRefGoogle Scholar
  113. G. Sarson, C. Jones, A convection driven geodynamo reversal model. Phys. Earth Planet. Inter. 111, 3–20 (1999) ADSCrossRefGoogle Scholar
  114. A. Schult, Self-reversal of magnetization and chemical composition of titanomagnetites in basalts. Earth Planet. Sci. Lett. 4(1), 57–63 (1968) ADSCrossRefGoogle Scholar
  115. J.C. Shao, M. Fuller, T. Tanimoto, J.R. Dunn, D.B. Stone, Spherical harmonic analyses of paleomagnetic data: The time-averaged geomagnetic field for the past 5 myr and the brunhes-matuyama reversal. J. Geophys. Res. 104(B3), 5015–5030 (1999) ADSCrossRefGoogle Scholar
  116. R. Simitev, F. Busse, Prandtl-number dependence of convection-driven dynamos in rotating spherical fluid shells. J. Fluid Mech. 532, 365–388 (2005) zbMATHMathSciNetADSCrossRefGoogle Scholar
  117. B.S. Singer, K.A. Hoffman, R.S. Coe, L.L. Brown, B.R. Jicha, M.S. Pringle, A. Chauvin, Structural and temporal requirements for geomagnetic field reversal deduced from lava flows. Nature 434, 633–636 (2005) ADSCrossRefGoogle Scholar
  118. P.J. Smith, Field reversal or self-reversal? Nature 229(5284), 378–380 (1971) ADSCrossRefGoogle Scholar
  119. B. Sreenivasan, C. Jones, Azimuthal winds, convection and dynamo action in the polar regions of planetary cores. Geophys. Astrophys. Fluid Dyn. 100, 319–339 (2006) MathSciNetADSCrossRefGoogle Scholar
  120. F. Stacey, Physics of the Earth (Brookfield Press, Brisbane, 1992) Google Scholar
  121. J. Stoner, J. Channell, D. Hodell, C.D. Charles, A 580 kyr paleomagnetic record from the sub-antarctic south Atlantic (ocean drilling program site 1089). J. Geophys. Res. 108, 2244 (2003). doi: 10.1029/2001JB001390 ADSCrossRefGoogle Scholar
  122. F. Takahashi, M. Matsushima, Y. Honkura, Simulations of a quasi-Taylor state geomagnetic field including polarity reversals on the Earth simulator. Science 309, 459–461 (2005) ADSCrossRefGoogle Scholar
  123. F. Takahashi, M. Matsushima, Y. Honkura, A numerical study on magnetic polarity transition in an MHD dynamo model. Earth Planets Space 59, 665–673 (2007) ADSGoogle Scholar
  124. F. Takahashi, M. Matsushima, Y. Honkura, Scale variability in convection-driven MHD dynamos at low Ekman number. Phys. Earth Planet. Inter. 167, 168–178 (2008) ADSCrossRefGoogle Scholar
  125. F. Theyer, E. Herrero-Bervera, V. Hsu, The zonal harmonic model of polarity transitions: a test using successive reversals. J. Geophys. Res. 90, 1963–1982 (1985) ADSCrossRefGoogle Scholar
  126. J.-P. Valet, E. Herrero-Bervera, Some characteristics of geomagnetic reversals inferred from detailed volcanic records. Compt. Ren. Geosci. 335, 79–90 (2003) ADSCrossRefGoogle Scholar
  127. J.-P. Valet, L. Tauxe, B.M. Clement, Equatorial and mid-latitude records of the last geomagnetic reversal from the Atlantic ocean. Earth Planet. Sci. Lett. 94, 371–384 (1989) ADSCrossRefGoogle Scholar
  128. J.-P. Valet, P. Tucholka, V. Courtillot, L. Meynadier, Palaeomagnetic constraints on the geometry of the geomagnetic field during reversals. Nature 356, 400–407 (1992) ADSCrossRefGoogle Scholar
  129. J.-P. Valet, L. Meynadier, Y. Guyodo, Geomagnetic dipole strength and reversal rate over the past two million years. Nature 435, 802–805 (2005) ADSCrossRefGoogle Scholar
  130. J.-P. Valet, G. Plenier, E. Herrero-Bervera, Geomagnetic excursions reflect an aborted polarity state. Earth Planet. Sci. Lett. 274, 472–478 (2008) ADSCrossRefGoogle Scholar
  131. J. Vogt, B. Zieger, K.-H. Glassmeier, A. Stadelmann, M.-B. Kallenrode, M. Sinnhuber, H. Winkler, Energetic particles in the paleomagnetosphere: Reduced dipole configurations and quadrupolar contributions. J. Geophys. Res. 112, A06216 (2007). doi: 10.1029/2006JA012224 CrossRefGoogle Scholar
  132. J. Wicht, Inner-core conductivity in numerical dynamo simulations. Phys. Earth Planet. Inter. 132, 281–302 (2002) ADSCrossRefGoogle Scholar
  133. J. Wicht, Palaeomagnetic interpretation of dynamo simulations. Geophys. J. Int. 162, 371–380 (2005) ADSCrossRefGoogle Scholar
  134. J. Wicht, P. Olson, A detailed study of the polarity reversal mechanism in a numerical dynamo model. Geophys. Geochem. Geosyst. 5 (2004). doi: 10.1029/2003GC000602
  135. J. Wicht, A. Tilgner, Theory and modeling of planetary dynamos. Space Sci. Rev. 152, 501–542 (2010) ADSCrossRefGoogle Scholar
  136. J. Wicht, S. Stellmach, H. Harder, Numerical models of the geodynamo: From fundamental Cartesian models to 3D simulations of field reversals, in Geomagnetic Field Variations—Space-Time Structure, Processes, and Effects on System Earth, ed. by H. Glassmeier, H. Soffel, J. Negendank (Springer, Berlin, 2009) Google Scholar
  137. J. Wicht, S. Stellmach, H. Harder, Numerical dynamo simulations–from basic concepts to realistic models, in Handbook of Geomathematics (Springer, Berlin, 2010) Google Scholar
  138. I. Williams, M. Fuller, Zonal harmonic models of reversal transition fields. J. Geophys. Res. 86(B12), 11657–11665 (1981) ADSCrossRefGoogle Scholar
  139. P. Willis, B. Sreenivasan, D. Gubbins, Thermal core-mantle interaction: Exploring regimes for ‘locked’ dynamo action. Phys. Earth Planet. Inter. 165, 83–92 (2007) ADSCrossRefGoogle Scholar
  140. H.-U. Worm, A link between geomagnetic reversals and events and glaciations. Earth Planet. Sci. Lett. 147, 55–67 (1997) ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  1. 1.Laboratoire de Planétologie et de Géodynamique, UMR 6112Nantes Atlantiques Universités, CNRS, Université de NantesNantesFrance
  2. 2.Central Institute for Meteorology and Geodynamics (ZAMG)ViennaAustria
  3. 3.Max-Planck-Institut für SonnensystemforschungKatlenburg-LindauGermany

Personalised recommendations