Hartmut A. Spetzler

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The sound velocities and single-crystal elastic constants of Fo89 hydrous ringwoodite ( Mg1.7Fe0.22H0.16SiO4) containing ∼10,000 ppm by weight (1 wt.%) H2O have been determined from seven separate pure-mode travel-time measurements using gigahertz ultrasonic interferometry. The experiments feature a new Yttrium–Aluminum–Garnet (YAG) P-to-S conversion shear(More)
[1] Knowledge of the elastic properties and crystal chemistry of dense oxide structures plays an important role in interpreting the composition and mineralogy of planetary interiors. We report the effects of (Mg,Fe) substitution and nonstoichiometry due to Fe on the crystal structure, elastic constants (cij) and moduli (K0T, K0S, G0) of (Mg,Fe)O utilizing(More)
Our knowledge of the Earth’s structure is based upon seismological data. Comparison between laboratory data and seismological data can provide information about the chemistry and mineralogy of Earth’s interior. Silicate perovskite and (Mg,Fe)O are likely to be important constituents of the lower mantle (e.g., Anderson 1989). Because of its wide stability(More)
The emerging picture of Earth's deep interior from seismic tomography indicates more complexity than previously thought. The presence of lateral anisotropy and heterogeneity in Earth's mantle highlights the need for fully anisotropic elasticity data from mineral physics. A breakthrough in high-frequency (gigahertz) ultrasound has resulted in transmission of(More)
A laboratory technique that allows strain measurements of the skull is described. Holographic interferometry allows the entire surface displacement of the skull to be mapped within 1/10 of the wavelength of light. Holographic interferometric pictures are presented following various stress applications to the skull. The method, besides being exquisitely(More)
Two new diamond anvil cells have been designed for ultrasonic and X-ray diffraction measurements on a single crystal sample up to 6 GPa and 250 oC. Advances in the generation and transmission of coherent GHz ultrasonic signals with wavelengths of the order of micrometers now make it practical to measure elastic properties of samples small enough to be(More)
A new method of generating shear waves with near-optical wavelength has been developed for gigahertz ultrasonic interferometry. The new acoustic technique features a P-to-S conversion upon reflection inside an MgO buffer rod, and is used first to determine the full set of ambient P–T elastic constants (ci j ) of magnesiowüstite—(Mg, Fe)O. In addition,(More)
We have examined the effect of surface contamination on the attenuation and stiffness of compressional seismic waves in artificial cylindrical glass cracks that are partially saturated with water. The compression of the gap perpendicularly to its plane reduces the gap volume and forces the water to redistribute within the gap (conservation of volume of an(More)