[SIT31-P02] Mercury core size constrained from elastic properties of Fe-Ni-S-Si liquid
Keywords:Mercury, Sound velocity, iron-alloy, Core
In this study, we measured the VP of liquid Fe–Ni–S–Si up to 17 GPa and investigated the effect of pressure and alloying of S+Si on the VP to constrain the radius of Mercury core. High pressure experiments were performed using 1500 ton Kawai-type multianvil press at BL04B1 beamline, SPring-8 synchrotron facility. The P-wave velocity was measured using the pulse-echo overlap method.
The VP of Fe-Ni-S-Si liquids of this study locate in between reported VP of Fe-Ni-S and Fe-Ni-Si. Thus, there is an offset between S and Si effects on the VP. Based on the obtained elastic properties of liquid Fe-Ni-S-Si, we estimated the Mercury core radius which satisfies the observed total mass and moment of inertia of Mercury and discuss possible core composition.