TY - JOUR
T1 - Sound velocity measurement in liquid water up to 25 GPa and 900 K
T2 - Implications for densities of water at lower mantle conditions
AU - Asahara, Yuki
AU - Murakami, Motohiko
AU - Ohishi, Yasuo
AU - Hirao, Naohisa
AU - Hirose, Kei
N1 - Funding Information:
The valuable discussions at ISEI are greatly appreciated. We thank T. Tange and M. Mastui for their helpful advice. We appreciate D.J. Frost for his constructive suggestions. We thank T. Takemoto and T. Kobayashi for their technical support at SPring-8, and W. Wagner for kindly providing the software for the IAPWS-95 Formulation. Y. A. was partially supported by a JSPS research fellowship for young scientists. This study was performed under the approval of proposal numbers 2006A0099, 2006B0099 and 2007A0099 2007B0099 2008A0099 of SPring-8. This study was supported by a Grant-in-Aid for ‘Stagnant Slab Project’ in Scientific Research on Priority Areas by the Ministry of Education, Culture, Sports, Science and Technology, Japan .
PY - 2010/1/31
Y1 - 2010/1/31
N2 - We extended the pressure range of sound velocity measurements for liquid water to 25 GPa and 900 K along the melting curve using a laser heated diamond anvil cell with a combined system of Brillouin scattering and synchrotron X-ray diffraction. Experimental pressure and temperature were obtained by solving simultaneous equations: the melting curve of ice and the equation of state for gold. The sound velocities obtained in liquid water at high pressures and melting temperatures were converted to density using Murnaghan's equation of state by fitting a parameter of the pressure derivative of bulk modulus at 1 GPa. The results are in good agreement with the values predicted by a previously reported equation of state for water based on sound velocity measurements. The equation of state for water obtained in this study could be applicable to water released by dehydration reactions of dense hydrous magnesium silicate phases in cold subducting slabs at lower mantle conditions, although the validity of Murnaghan's equation of state for water should be evaluated in a wider pressure and temperature ranges. The present velocity data provides the basis for future improvement of the accurate thermodynamic model for water at high pressures.
AB - We extended the pressure range of sound velocity measurements for liquid water to 25 GPa and 900 K along the melting curve using a laser heated diamond anvil cell with a combined system of Brillouin scattering and synchrotron X-ray diffraction. Experimental pressure and temperature were obtained by solving simultaneous equations: the melting curve of ice and the equation of state for gold. The sound velocities obtained in liquid water at high pressures and melting temperatures were converted to density using Murnaghan's equation of state by fitting a parameter of the pressure derivative of bulk modulus at 1 GPa. The results are in good agreement with the values predicted by a previously reported equation of state for water based on sound velocity measurements. The equation of state for water obtained in this study could be applicable to water released by dehydration reactions of dense hydrous magnesium silicate phases in cold subducting slabs at lower mantle conditions, although the validity of Murnaghan's equation of state for water should be evaluated in a wider pressure and temperature ranges. The present velocity data provides the basis for future improvement of the accurate thermodynamic model for water at high pressures.
KW - Brillouin scattering
KW - diamond anvil cell
KW - lower mantle
KW - sound velocity
KW - synchrotron X-ray diffraction
KW - water
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U2 - 10.1016/j.epsl.2009.11.037
DO - 10.1016/j.epsl.2009.11.037
M3 - Article
AN - SCOPUS:73449134055
VL - 289
SP - 479
EP - 485
JO - Earth and Planetary Sciences Letters
JF - Earth and Planetary Sciences Letters
SN - 0012-821X
IS - 3-4
ER -