Thermophysical Properties and Phase Changes in the Upper Mantle

The correlation between phase changes within the upper mantle and the thermophysical properties of the minerals therein has been investigated by using the thermoelastic and thermodynamic equations. The depth dependence data of seismic velocities of Jeffreys–Bullen and density within the upper mantle are used as inputs in the analysis. The material characteristic properties like Debye temperature,ΘD, adiabatic compressibility, κS, Grüneisen parameter, ξ, and the specific heat capacity, CP computed as a function of depth show clearly two discontinuities at average depths of 414 km and 645 km which are in fair agreement with the presently accepted depths 410 km and 670 km from the preliminary reference earth model data.