Moscow, Moscow, Russian Federation
UDC 55
UDC 550.34
UDC 550.383
CSCSTI 37.01
CSCSTI 37.15
CSCSTI 37.25
CSCSTI 37.31
CSCSTI 38.01
CSCSTI 36.00
CSCSTI 37.00
CSCSTI 38.00
CSCSTI 39.00
CSCSTI 52.00
Russian Classification of Professions by Education 05.00.00
Russian Library and Bibliographic Classification 26
Russian Trade and Bibliographic Classification 63
BISAC SCI SCIENCE
According to the model of the Earth’s cooling, before the solid core origin, there was a sub-adiabatic layer at the core-mantle boundary several hundred kilometers thick. In this layer magnetic field generation was suppressed. Removing the field generation region from the Earth’s surface led to an effective weakening of the small-scale component of the magnetic field. After the solid core appeared, convection extended throughout the whole bulk of the core with the possible exception of the F-layer at the core-mantle boundary, which is no more than 100 km thick. As a result the non-dipole counterpart of the magnetic field should be stronger at the Earth’s surface. The decrease of the ratio of the dipole to non-dipole field with the origin of the solid core was an order of magnitude or more.
geodynamo, core-mantle boundary, Earth’s cooling, inner core
1. Abe Y. Physical state of the very early Earth // Lithos. — 1993. — Vol. 30, no. 3/4. — P. 223–235. — https://doi.org/10.1016/0024-4937(93)90037-d.
2. Aubert J. State and evolution of the geodynamo from numerical models reaching the physical conditions of Earth’s core // Geophys. J. Int. — 2023. — Vol. 235, no. 1. — P. 468–487. — https://doi.org/10.1093/gji/ggad229.
3. Braginsky S.I. Structure of the F layer and reasons for convection in the Earth’s core // Dokl. Akad. Nauk. SSSR Engl. Trans. — 1963. — Vol. 149. — P. 1311–1314.
4. Christensen U. Geodynamo models with a stable layer and heterogeneous heat flow at the top of the core // Geophys. J. Int. — 2018. — Vol. 215, no. 2. — P. 1338–1351. — https://doi.org/10.1093/gji/ggy352.
5. Christensen U. and Aubert J. Scaling properties of convection-driven dynamos in rotating spherical shells and application to planetary magnetic fields // Geophys. J. Int. — 2006. — Vol. 166. — P. 97–114. — https://doi.org/10.1111/j.1365-246X.2006.03009.x.
6. Christensen U., Aubert J. and Hulot G. Conditions for Earth-like geodynamo models // Earth Planet. Sci. Lett. — 2010. — Vol. 296, no. 3/4. — P. 487–496. — https://doi.org/10.1016/j.epsl.2010.06.009.
7. Gastine T., Aubert J. and Fournier A. Dynamo-based limit to the extent of a stable layer atop Earth’s core // Geophys. J. Int. — 2020. — Vol. 222, no. 2. — P. 1433–1448. — https://doi.org/10.1093/gji/ggaa250.
8. Gubbins D., Alfè D., Davies C.J., et al. On core convection and the geodynamo: Effects of high electrical and thermal conductivity // Phys. Earth Planet. Int. — 2015. — Vol. 247. — P. 56–64. — https://doi.org/10.1016/j.pepi.2015.04.002.
9. Gubbins D. and Davies C.J. The stratified layer at the core–mantle boundary caused by barodiffusion of oxygen, sulphur and silicon // Phys. Earth Planet. Int. — 2013. — Vol. 215. — P. 21–28. — https://doi.org/10.1016/j.pepi.2012.11.001.
10. Gubbins D., Thomson C.J. and Whaler K.A. Stable regions in the Earth’s liquid core // Geophys. J. Roy. Astr. Soc. — 1982. — Vol. 68, no. 1. — P. 241–251. — https://doi.org/10.1111/j.1365-246X.1982.tb06972.x.
11. Labrosse S., Poirier J.-P. and Le Mouël J.-L. On cooling of the Earth’s core // Phys. Earth Planet. Int. — 1997. — Vol. 99, no. 1. — P. 1–17. — https://doi.org/10.1016/S0031-9201(96)03207-4.
12. Labrosse S., Poirier J.-P. and Le Mouël J.-L. The age of the inner core // Earth Planet. Sci. Lett. — 2001. — Vol. 190, no. 3/4. — P. 111–123. — https://doi.org/10.1016/S0012-821X(01)00387-9.
13. Lowes F.J. Spatial power spectrum of the main geomagnetic field // Geophys. J. R. Astr. Soc. — 1974. — Vol. 36. — P. 717–725. — https://doi.org/10.1111/j.1365-246x.1974.tb00622.x.
14. Nichols C.I.O., Weiss B.P., Eyster A., et al. Eoarchean records of the geomagnetic field preserved in the Isua Supracrustal Belt, southern west Greenland // J. Geophys. Res. Solid Earth. — 2024. — Vol. 129, no. 4. — e2023JB027706. — https://doi.org/10.1029/2023JB027706.
15. Olson P. The new core paradox // Science. — 2013. — Vol. 342, no. 6157. — P. 431–432. — https://doi.org/10.1126/science.1243477.
16. Reshetnyak M.Yu. Evolution of the inner core of the Earth: consequences for geodynamo // Magnetohydrodynamics. — 2019. — Vol. 55, no. 1/2. — P. 175–183.
17. Reshetnyak M.Yu. Mantle cooling regulation and ancient geomagnetic field // Russ. J. Earth Sci. — 2022. — Vol. 22. — ES2006. — https://doi.org/10.2205/2022ES000797.
18. Roberts P.-H., Jones C.A. and Calderwood A.R. Energy fluxes and ohmic dissipation in the Earth’s core // Earth’s core and lower mantle / ed. by C.A. Jones, A.M. Soward and K. Zhang. — Taylor, Francis, 2003. — P. 100–129. — https://doi.org/10.1201/9780203207611.CH5.
19. Rogister Y. and Valette B. Influence of liquid core dynamics on rotation modes // Geophys. J. Int. — 2009. — Vol. 176. — P. 368–388. — https://doi.org/10.1111/j.1365-246X.2008.03996.x.
20. Smirnov A.V., Tarduno J.A., Kulakov E.V., et al. Palaeointensity, core thermal conductivity and the unknown age of the inner core // Geophys. J. Int. — 2016. — Vol. 205, no. 2. — P. 1190–1195. — https://doi.org/10.1093/gji/ggw080.
21. Takehiro S. and Lister J.R. Penetration of columnar convection into an outer stably stratified layer in rapidly rotating spherical fluid shells // Earth Planet. Sci. Lett. — 2001. — Vol. 187, no. 3/4. — P. 357–366. — https://doi.org/10.1016/S0012-821X(01)00283-7.




