JpGU-AGU Joint Meeting 2017

Presentation information

[EE] Oral

S (Solid Earth Sciences) » S-IT Science of the Earth's Interior & Tectonophysics

[S-IT22] [EE] Interaction and Coevolution of the Core and Mantle in the Earth and Planets

Mon. May 22, 2017 3:30 PM - 5:00 PM Convention Hall B (International Conference Hall 2F)

convener:Taku Tsuchiya(Geodynamics Research Center, Ehime University), Hidenori Terasaki(Graduate School of Science, Osaka University), Madhusoodhan Satish-Kumar(Department of Geology, Faculty of Science, Niigata University), Tetsuo Irifune(Geodynamics Research Center, Ehime University), John Hernlund(Earth-Life Science Institute, Tokyo Institute of Technology), Eiji Ohtani(Department of Earth and Planetary Materials Science, Graduate School of Science, Tohoku University), Chairperson:Taku Tsuchiya(Geodynamics Research Center, Ehime University)

4:30 PM - 4:45 PM

[SIT22-41] Thermoelastic properties of iron-carbide melts under high pressure: implication for carbon in the lunar interior

*Yuta Shimoyama1, Hidenori Terasaki1, Satoru Urakawa2, Yusaku Takubo1, Tetsu Watanuki3, Akihiko Machida3, Yoshinori Katayama3, Tadashi Kondo1 (1.Dept. Earth&Space Science, Osaka University, 2.Graduate School of Natural Science and technology, Okayama University,, 3.Natural Institutes for Quantum and Radiological Science and Technology)

Keywords:Moon, Outer core, liquid, sound velocity, density, bulk modulus

Carbon is one of the possible light elements in lunar interior. Thus, it is important to understanding the effect of density and sound velocity of liquid Fe at high pressure in order to evaluate the presence of carbon in lunar core. Simultaneous measurements of P-wave velocity and the density of liquid Fe-C have been conducted up to 3.4 GPa and 1850 K. Addition of carbon decreased the VP of liquid Fe by about 2% at 3 GPa and 1700 K and reduced Fe density by about 2% at 2 GPa and 1700 K. The VP of liquid Fe-3.5 wt% C decreased linearly with increasing temperature at constant pressure. The bulk modulus of liquid Fe-C and its pressure (P) and temperature (T) effects were precisely determined from directly measured r and VP data to be K0,1700K = 83.9 GPa, dKT/dP = 5.9(2), and dKT/dT = −0.063(8) GPa/K. The effect of carbon in the Birch (r–VP) plot decreases with increasing pressure. Based on the directly measured VP and r of liquid Fe-C, elastic properties, such as K, dK/dT, and dK/dP, were determined precisely. These properties can explain differences in dVP/dT of Fe-C, Fe, and Fe-S.