Determination of thermal expansivity of the mantle minerals
Temperature is the most fundamental parameter to discuss the dynamics of the Earth's interior. Nevertheless, the temperature distribution in the deep mantle is not well constrained. The mantle geotherm is considered nearly adiabatic, because heat is mainly transferred by convection in the majority of the mantle. The adiabatic temperature gradient is given by:
(dT/dz)S = αgT/CP
where α is the thermal expansivity, g is the gravity acceleration, CP is the isobaric heat capacity. Since the gravity acceleration and isobaric heat capacity in the mantle do not vary largely, the thermal expansion coefficient is a key parameter to estimate the temperature distribution in the deep mantle. we determined thermal expansion coefficient of mantle minerals under conditions realistic for deep mantle.
Katsura, T., K. Funakoshi, A. Kubo, N. Nishiyama, Y. Tange, Y. Sueda, T. Kubo, and W. Utsumi (2004), A large-volume high-pressure and high-temperature apparatus for in situ X-ray observation, 'SPEED-Mk.II', Phys. Earth Planet. Inter., 143, 497-506.
EOS of olivine
Katsura, T., et al. (2009), Thermal expansion of forsterite at high pressures determined by in situ X-ray diffraction: The adiabatic geotherm in the upper mantle, Phys. Earth Planet. Inter., 174(1-4), 86-92.
EOS of wadsleyite
EOS of ringwoodite
EOS of bridgmanite
Katsura, T., et al. (2009), P-V-T
relations of MgSiO3 perovskite determined by in situ X-ray diffraction using a large-volume high-pressure apparatus, Geophys. Res. Lett., 36.
Errata: Correction to “P-V-T relations of the MgSiO3 perovskite determined by in situ X-ray diffraction using a large-volume high-pressure apparatus”
Adiabatic temperature profile