Experimental study of gravitational instability using high power laser: Implication to early Earth differentiation

2015 Fiscal Year Final Research Report

• Project/Area Number: 26610141
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Solid earth and planetary physics
• Research Institution: Osaka University
• Principal Investigator: Terasaki Hidenori 大阪大学, 理学(系)研究科(研究院), 准教授 (50374898)
• Co-Investigator(Renkei-kenkyūsha): SAKAIYA Tatsuhiro 大阪大学, 大学院理学研究科, 助教 (60452421)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 惑星核形成 / 重力不安定 / 鉄合金 / レーザー衝撃実験 / 核ーマントル分離

Outline of Final Research Achievements

In order to clarify the core/mantle differentiation process controlled by gravitational instability, we have carried out in situ observation of gravitational instability of Fe-alloy under high pressure and temperature. By adding gravity to the sample using high power laser (GEKKO-XII), a surface perturbation of the sample was measured based on X-ray absorption imaging. It is found that an amplitude of the perturbation increased with time and that growth rate of the perturbation changed depending on the sample composition and existence of silicate layer on the sample. In this study, we successfully measured the perturbation growth of Fe-alloy samples caused by gravitational instability. The obtained results give us important information regarding terrestrial core formation mechanism and its time scale.

Free Research Field

高圧地球科学