Temperature dependence of elastic moduli of β-(Mg, Fe)2SiO4 -: art. no. L04612

The elastic moduli of polycrystalline wadsleyite, beta-(Mg0.91Fe0.09)(2)SiO4, were measured up to 470 K by means of the resonant sphere technique. The adiabatic bulk (K-S) and shear (mu) moduli were found to be 165.72( 6) and 105.43(2) GPa at room temperature. The average slopes (dK(S)/dT and dmu/dT) in the range were determined to be - 0.0175(3) and - 0.0159(1) GPa/K. We estimated that the P-, S-wave velocity and density jumps for the alpha- to beta-phase transformation at the 410-km depth condition were 9.5, 11.2 and 5.4%, respectively. These results suggest that the olivine component at the depth should be 52 and 42 volume % for P- and S-waves.