Anisotropy of the Earth's inner core studied by high-pressure deformation experiments
| Project/Area Number |
15H03749
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
岩石・鉱物・鉱床学
|
|---|
| Research Institution | Ehime University |
|---|
Principal Investigator |
Nishihara Yu 愛媛大学, 地球深部ダイナミクス研究センター, 准教授 (10397036)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
太田 健二 東京工業大学, 理学院, 准教授 (20727218)
大内 智博 愛媛大学, 地球深部ダイナミクス研究センター, 講師 (60570504)
松影 香子 帝京科学大学, 総合教育センター, 准教授 (80343078)
|
|---|
| Research Collaborator |
SETO yusuke
HIGO yuji
|
|---|
| Project Period (FY) |
2015-04-01 – 2019-03-31
|
| Project Status |
Completed (Fiscal Year 2018)
|
| Budget Amount *help |
¥16,640,000 (Direct Cost: ¥12,800,000、Indirect Cost: ¥3,840,000)
Fiscal Year 2018: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
Fiscal Year 2017: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
Fiscal Year 2016: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
Fiscal Year 2015: ¥7,670,000 (Direct Cost: ¥5,900,000、Indirect Cost: ¥1,770,000)
|
|---|
| Keywords | 地球中心核 / hcp鉄 / 高温高圧変形実験 / 結晶選択配向 / 地震波異方性 / 格子選択配向 |
|---|
| Outline of Final Research Achievements |
To investigate formation mechanism of the seismic anisotropy in the Earth’s inner core, we conducted deformation experiments and thermal conductivity measurements on hcp-iron. Crystallographic-preferred orientation determined by the deformation experiments suggests predominance of basal slip in hcp-iron, and the strength of the calculated anisotropy is comparable to the inner core anisotropy. Thermal conductivity measurements revealed that the hcp-iron has a strong anisotropy where the thermal conductivity varies by a factor of 3-4 depending on crystallographic orientation. This strong anisotropy may enhance temperature heterogeneity in the inner core.
|
| Academic Significance and Societal Importance of the Research Achievements |
地球中心に位置する内核を南北の極方向に伝播する縦波（P波）は赤道方向へ伝播するものに比べて約3%も高速であることが知られている（地震波速度異方性）。この原因として、様々な仮説が提唱されてきたが、いまだに一致した見解は得られていない。本研究の結果は内核内での変形流動により結晶が特定方位に配列することで内核の地震波速度異方性がうまく解釈できることを示し、この謎を解き明かすうえでの判断材料を提供した。
|
Report
(5 results)
Research Products
(46 results)
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
[Journal Article] EDS quantification of light elements using osmium surface coating2015
Author(s)
Ohuchi, T., Nishihara, Y., Seto, Y., Kawazoe, T., Nishi, M., Maruyama, G., Hashimoto, M., Higo, Y., Funakoshi, K.-I., Suzuki, A., Kikegawa, T., Irifune, T.
-
Journal Title
J. Min. Petrol. Sci.
Volume: 243
Pages: 189-195
DOI
NAID
Related Report
Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
-
-
-
-
-
-
-
-
-
-
-
-
-
[Presentation] Defomation microstructures of subducted slabs in the lower mantle2018
Author(s)
Azuma, S., Nomura, R., Uesugi, K., Nishihara, Y., Doi, S., Arimoto, T. and Irifune, T.
Organizer
AGU Fall Meeting 2018
Related Report
Int'l Joint Research
-
-
-
-
-
-
[Presentation] Is thermal conductivity of hcp iron anisotropic?2017
Author(s)
Ohta, K., Sato, Y., Nishihara, Y., Yagi, T., Hirose, K., Kawaguchi-Imada, S., Hirao, N. and Ohishi, Y.
Organizer
High-Pressure Mineral Physics Seminar (HPMPS-9)
Related Report
Int'l Joint Research
-
-
-
-
-
-
-
-
-
-
-
-
