## Abstract

Elasticity of (Mg_{0.87}Fe_{0.13})_{2}SiO_{4} wadsleyite has been measured at simultaneous high pressure and high temperature to 12 GPa and 1073 K using ultrasonic interferometry in conjunction with synchrotron X-radiation. The elastic moduli and their pressure and temperature derivatives are precisely determined using pressure-standard-free third-order and fourth-order finite strain equations. Combined with previous thermoelastic data on olivine, the density, velocity and acoustic impedance contrasts between α- and β-(Mg_{0.9}Fe_{0.1})_{2}SiO_{4} at 410-km depth are calculated along a 1673 K adiabatic geotherm. Both the third- and fourth-order finite strain equation fitting results give estimation of ∼33-58% olivine content in the upper mantle to account for a seismic discontinuity of ∼5% velocity jumps, and 8.5% (P wave) and 11.1% (S wave) impedance jumps at 410 km depth.

Original language | English |
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Pages (from-to) | 98-104 |

Number of pages | 7 |

Journal | Physics of the Earth and Planetary Interiors |

Volume | 174 |

Issue number | 1-4 |

DOIs | |

Publication status | Published - 2009 May 1 |

## All Science Journal Classification (ASJC) codes

- Astronomy and Astrophysics
- Geophysics
- Physics and Astronomy (miscellaneous)
- Space and Planetary Science