DETECTING A MAGNESIOWГњSTITE PHASE TRANSITION IN THE LOWER MANTLE BY INVERSION OF GEOMAGNETIC DATA
V.V. Plotkin1, P.G. Dyad’kov1, S.G. Ovchinnikov2
1A.A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia
2Kirensky Institute of Physics, Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk Akademgorodok 50, Building 38, Krasnoyarsk, 660036, Russia
Keywords: MagnesiowГјstite, metallic state, phase transition, lower mantle, conductivity, geomagnetic variations, global network
Abstract
Global geomagnetic data are inverted for detecting a high–conductivity layer at depths of 1500–2000 km to test the hypothesis of a magnesiowüstite phase transition in the lower mantle. The results of processing of both synthetic and global data — average monthly values of the geomagnetic field from 1920 to 2009 — are presented. The inverted global data are consistent with the possible existence of a high-conductivity layer at great depths in the lower mantle.
DOI: http://dx.doi.org/10.1016/j.rgg.2014.08.009
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