HR: 1330h
AN: V42A-0330    [PDF]
TI: Simultaneous Determination of Elastic and Structural Properties Under Simulated Mantle Conditions Using Multi-Anvil Device MAX80
AU: * Mueller, H J
EM: hjmuel@gfz-potsdam.de
AF: GeoForschungsZentrum Potsdam, Division 4, Telegraphenberg, Potsdam, D-14473 Germany
AU: Schilling, F R
EM: fsch@gfz-potsdam.de
AF: GeoForschungsZentrum Potsdam, Division 4, Telegraphenberg, Potsdam, D-14473 Germany
AU: Lathe, C
EM: christian.lathe@desy.de
AF: GeoForschungsZentrum Potsdam, Division 4, Telegraphenberg, Potsdam, D-14473 Germany
AB: The resolution and amount of seismic data from the Earth's deep interior increased dramatically during the last few years. To improve our understanding of Earth's deep interior, the interpretation of these data requires measurements of elastic properties of Earth materials under simulated mantle conditions, simultaneously at high pressure and temperature conditions,. We use ultrasonic interferometry to measure travel time with high precision, on samples enclosed in a high-pressure multi-anvil device (MAX80). In addition to travel times the determination of wave velocities requires the knowledge of the exact sample length under in situ conditions. Nowadays, two possibilities are used - scanning the interfaces of the sample (Mueller et al., 2003) and X-radiography (Li et al., 2001). Besides elastic properties structural characteristics are investigated at the same time. To determine travel time, the classical digital sweep interferometry is used, which is very time consuming. For example a 60 MHz frequency sweep with 100 kHz steps lasts for more than 30 minutes. Therefore, a single measurement of Vp and Vs requires more than 1 hour. This is a serious limitation for measurements under transient conditions and limits the data collection at elevated temperatures. To avoid this, an ultrasonic transfer function technique (UTF) was installed, related to the technique described by Li et al. (2002), which allows the generation and emission of all the frequencies simultaneously (Mueller et al., 2003). The "GFZ" type UTF technique allows to consider the characteristics of the transducer-glue-anvil combination (Mueller et al., 2003) and to determine Vp and Vs within less than 2 minutes. Some results on non-quenchable phase transitions will be given to discuss the different interferometric techniques. The precision of sample length determination by X-radiography will be compared to the scanning of the interface technique. Li, B.; Vaughan, M.T.; Kung, J.; Weidner, D.J., NSLS Activity Report 2001, 2-103-106, (2001). Li, B.; Chen, K.; Kung, J.; Liebermann, R.C.; Weidner, D.J., J. Phys.: Condens. Matter 14, 11337-11342, (2002). Mueller, H.J.; Wunder, B.; Lathe, C.; Schilling, F.R., Phys. Earth Plan. Int., submitted, (2003).
DE: 3900 MINERAL PHYSICS
DE: 3909 Elasticity and anelasticity
DE: 3954 X ray, neutron, and electron spectroscopy and diffraction
DE: 3994 Instruments and techniques
DE: 7207 Core and mantle
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting