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Published byKristina Willis Modified over 9 years ago
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Reconstructing the Phanerozoic Geodynamo Whole-Earth approach (mantle + core + time) to geodynamo history CMB heat flux from two models of the Phanerozoic mantle: 1.Mantle convection with mobile plates and continents (model HF1 by Zhang & Zhong, 2011) 2.Present-day lower mantle seismic heterogeneity Core evolution determined by CMB heat flux, including a)Inner core growth b)Chemical differentiation (Fe-Le) c)CMB heterogeneity d) Tidal breaking (via increase in length of day) Calculate dynamo time average magnetic fields and polarity reversals over 5 Myr long stages Tune dynamos to present-day (0-5 Ma) reversal rate
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Box Model: Core Evolution ~ 700 Myr T(r,t,) C(r,t) r ICB (t) 3D Model: Numerical Dynamo ~ 5 Myr stages T(x,t,) C(x,t) B(x,t) T(x,t,) C(x,t) B(x,t) Thermodynamic Parameters CMB Heat Flow Q(t) T(r,0), C(r,0), r ICB (0) Transport Parameters CMB Heat Flux q(x) (t) GPTS Reversals
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total ICB HF1 CMB heat flow Compositional breakup assembly Pangea Variable evolution Driver: mantle reconstruction HF1 (Zhang & Zhong, 2011) Regular evolution Driver: constant CMB heat flow Phanerozoic Core Evolution (thanks to Renaud!) Regular
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Parametric Core Evolution HF1 Regular E/E(0) Ra/Ra(0) Ma
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Present-day (0-5 Ma) Reversal Records
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Polarity Reversal Record Comparison
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GPTS (5.4 Myr)
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