Abstract
Numerical model calculations have been carried out to study the effect of the centrifugal force on the compositionally dense material accumulated in the lowermost mantle. The deformation of an initial dense layer encircling the core was investigated systematically as a function of the density difference between the lower dense and the overlaying mantle, β and the angular velocity of the planet, Ω in a two-dimensional cylindrical shell domain. It was established that increasing β does not influence the magnitude of the deformation of the dense layer but decreases the velocity of the deformation. The relaxation time of the deformation is inversely proportional to β similarly to post-glacial rebound. On the other hand, increasing Ω enhances the magnitude of the deformation but does not affect the deformation relaxation time. The magnitude of the deformation is approximately proportional to Ω2. It was pointed out that for the present-day mantle parameters, β = 2–4 % and Ω = 7.3 × 10−5 1/s the equatorial elevation of the dense layer is about 2 km which more than two orders of magnitude less than the height of the seismically observed large low shear velocity provinces beneath Africa and Pacific. During the Earth’s history when the rotation of our planet was faster the influence of the centrifugal force was much more significant and the equatorial elevation of the dense layer might have reached even 100 km.
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References
Binder AB (1982) The Moon: its figure and orbital evolution. Geophys Res Lett 9(1):33–36
Bott MHP (1982) The interior of the earth: its structure, constitution and evolution, 2nd edn. Elsevier, London
Canup RM, Asphaug E (2001) Origin of the Moon in a giant impact near the end of the Earth’s formation. Nature 412(6848):708–712
Chandrasekhar S (1961) Hydrodynamic and hydromagnetic stability. Clarendon, Oxford
Christensen U, Olson P, Glatzmaier GA (1999) Numerical modelling of the geodynamo: a systematic parameter study. Geophys J Int 138(2):393–409
Dickey JO, Ghil M, Marcus SL (1990) A 30–60 day oscillation in length-of-day and atmospheric angular momentum: extratropical origin? In: Boucher C, Wilkins GA (eds) Earth rotation and coordinate reference frames. Springer, New York, pp 90–97
Dziewonski AM, Lekic V, Romanovicz BA (2010) Mantle anchor structure: an argument for bottom up tectonics. Earth Planet Sci Lett 299(1–2):69–79
Eriksson KA, Simpson EL (2000) Quantifying the oldest tidal record: the 3.2 Ga Moodies Group, Barberton greenstone belt, South Africa. Geology 28(9):831–834
Galsa A, Herein M, Lenkey L, Farkas MP, Taller G (2015) Effective buoyancy ratio: a new parameter characterizing thermo-chemical mixing in the Earth’s mantle. Solid Earth 6:93–102
Garnero E, McNamara A (2008) Structure and dynamics of Earth’s lower mantle. Science 320(5876):626–628
Garnero EJ, Lay T, McNamara A (2007) Implication of lower-mantle structural heterogeneity for existence and nature of whole-mantle plumes. Geol Soc Am Spec Pap 430:79–101
Glukhovskii MZ, Kuz’min MI (2015) Extraterrestrial factors and their role in the Earth’s tectonic evolution in the early Precambrian. Russ Geol Geophys 56(15):959–977
Harrison TM (2006) Exploring the hadean earth. Geochim Cosmochim Acta 70(18S):A234
Haskell NA (1935) The motion of a fluid under the surface load. Physics 6:265–269
Hazen R (2012) The story of earth: the first 4.5 b years, from stardust to living planet. Viking, New York
Ishii M, Tromp J (2004) Constraining large-scale mantle heterogeneity using mantle and inner-core sensitive normal modes. Phys Earth Planet Inter 146(1–2):113–124
Kamphuis V, Huisman SE, Dijkstra HA (2011) The global ocean circulation on a retrograde rotating earth. Clim Past 7(2):487–499
Koelemeijer PJ, Deuss A, Trampert J (2012) Normal mode sensitivity to Earth’s D’’ layer and topography on the core-mantle boundary: what we can and cannot see. Geophys J Int 190(1):553–568
Labrosse S, Hernlund JW, Coltice N (2007) A crystallizing dense magma ocean at the base of Earth’s mantle. Nature 450(7171):866–869
Lay T, Garnero EJ, Williams Q (2004) Partial melting in a thermo-chemical boundary layer at the base of the mantle. Phys Earth Planet Inter 146(3–4):441–467
Li Y, Dechamps F, Tackley PJ (2014) The stability and structure of primordial reservoirs in the lower mantle: insights from models of thermochemical convection in three-dimensional spherical geometry. Geophys J Int 199:914–930
Mao WL, Shu JF, Hu JZ, Hemley R, Mao H (2002) Displacive transition in magnesiowüstite. J Phys-Condens Matter 14(44):11349–11354
Marakushev AA, Zinov’eva NG, Paneyakh NA, Marakushev SA (2013) The origin and evolution of the solar system. Prostran i Vremya 2(12):132–141
Marschall J, Scott F (1999) Open-ocean convection: observations, theory, and models. Rev Geophys 37(1):1–64
Scheel J (2007) Rotating rayleig-bénard convection. Dissertation, California Institute of Technology
Schubert G, Turcotte D, Olson P (2001) Mantle convection in the earth and planets. University Press, Cambridge
Tackley PJ (2012) Dynamics and evolution of the deep mantle resulting from thermal, chemical, phase and melting effects. Earth Sci Rev 110(1–4):1–25
Thorne MS, Garnero EJ, Grand S (2004) Geographic correlation between hot spots and deep mantle lateral shear-wave velocity gradients. Phys Earth Planet Inter 146(1–2):47–63
Torsvik TH, Steinberger B, Gurnis M, Gaina C (2010) Plate tectonics and net lithosphere rotation over the past 150 My. Earth Planet Sci Lett 291(1–4):106–112
Varga P (2006) Temporal variation of geodynamical properties due to tidal friction. J Geodyn 41(1–3):140–146
Varga P, Denis C, Varga T (1998) Tidal friction and its consequences in paleogeodesy, in the gravity field variations and in tectonics. J Geodyn 25(1):61–84
Wood B (2011) The formation and differentiation of Earth. Phys Today 64(12):40–45
Zhong J Q, Stevens R, Clercx H, Verzicco R, Lohse D, Ahlers G (2009) Prandtl-, Rayleigh-, and Rossby-number dependence of heat transport in turbulent rotating Rayleigh–Bénard convection. Physical Review Letters 102(4):044502
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This research was supported by the European Union and the State of Hungary, co-financed by the European Social Fund in the framework of TÁMOP 4.2.4. A/1-11-1-2012-0001 National Excellence Program and by the Hungarian Science Foundation under Grant number NK100296.
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Bozóki, T., Herein, M. & Galsa, A. Numerical evolution of the asymmetry in the compositionally inhomogeneous lower mantle driven by Earth’s rotation. Acta Geod Geophys 52, 331–343 (2017). https://doi.org/10.1007/s40328-016-0172-6
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DOI: https://doi.org/10.1007/s40328-016-0172-6