1) Measurement and calculation of density and sound velocity of lower mantle/subducted crustal materials at relevant P-T in order to test whether the lower mantle is chemically identical to the upper mantle.

2) Constraint of core composition from properties of liquid Fe alloys

2-1) Measurement and calculation of density and sound velocity of liquid Fe alloy at core P-T

2-2) Creation of phase diagrams relevant to inner core crystallization

2-3) Test feasibility of alloy compositions

3) Estimation of core composition from formation scenarios

4) Model Earth composition from planet formation theory


Understanding the composition, constitution, and dynamics of the present Earth’s interior is vital to address its origin and evolution. ELSI researchers study these subjects using state-of-the-art technologies of high-pressure experiments, synchrotron radiation, ab initio computations, and geophysical modeling. ELSI researchers are currently addressing the composition of the bulk Earth, by focusing particular attention on the uncertain composition of the lower mantle and core.


topic1a topic1b

The diamond anvil cell (DAC) and its enlarged view of the interior. The DAC can simulate extremely high pressures and temperatures up to the center of the Earth.


topic1c topic1d

The world’s largest multi-anvil high-pressure facility, and polycrystalline diamond installed in an anvil cell.