Effect of light element on rheology of hcp-iron: Structure and dynamics of the inner core

2016 Fiscal Year Final Research Report

• Project/Area Number: 26287136
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Petrology/Mineralogy/Economic geology
• Research Institution: Okayama University
• Principal Investigator: Yamazaki Daisuke 岡山大学, 惑星物質研究所, 准教授 (90346693)
• Co-Investigator(Kenkyū-buntansha): 米田 明 岡山大学, 地球物質科学研究センター, 准教授 (10262841) ; 芳野 極 岡山大学, 地球物質科学研究センター, 准教授 (30423338)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 内核 / 拡散 / 粒成長

Outline of Final Research Achievements

We determined the grain growth and diffusion rates of hcp iron and estimated the dominant deformation mechanism and viscosity of the inner core based on the experimental results. As a result, chemical heterogeneity is essential to interpret the observed heterogeneity between the eastern and western sides of the inner core in seismic attenuation. Moreover, we experimentally showed the small effect of Si on viscosity of hcp iron, indicating that light element(s) rather than Si may significantly affect the viscosity of the inner core.

Free Research Field

高圧地球科学