Ultra high resolution reconstruction of geomagnetic and environmental variations recorded in tree rings with SQUID microscope
| Project/Area Number |
16K13876
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Solid earth and planetary physics
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| Research Institution | National Institute of Advanced Industrial Science and Technology |
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Principal Investigator |
Oda Hirokouni 国立研究開発法人産業技術総合研究所, 地質調査総合センター, 上級主任研究員 (90356725)
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| Co-Investigator(Kenkyū-buntansha) |
佐藤 雅彦 東京大学, 大学院理学系研究科(理学部), 助教 (50723277)
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| Research Collaborator |
Miyahara Hiroko
Kawai Jun
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000)
Fiscal Year 2017: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2016: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
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| Keywords | 樹木年輪 / 赤松 / SQUID磁気顕微鏡 / 春目 / 夏目 / 磁気イメージング / 自然残留磁化 / 等温残留磁化 / SQUID顕微鏡 / 高感度分析 / 非履歴性残留磁化 / コンタミ / 火山灰 / 環境岩石磁気 / 古地磁気 |
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| Outline of Final Research Achievements |
We conducted continuous magnetic imaging of a thin section of a tree using scanning SQUID microscope. For the purpose of high sensitivity measurements, we improved signal-to-noise ratio and measurements were performed in a clean environments without dust particles. We prepared 1mm thickness sample of a tree trunk of a red pine of 4 cm length from the bark and polished on both sides. Surface magnetic fields were less than about 0.2 nT as natural state. After exposing to a vertical magnetic field of 2T, surface magnetic fields of a few nT were observed as stripes parallel to the annual growth rings. Strong magnetic field corresponds to spring layers with high growth composed of less dense material. Spring layer has reddish brown spots, which might be related to the strong magnetic signals observed.
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| Academic Significance and Societal Importance of the Research Achievements |
本研究により、赤松の樹幹部分の年輪から年変動に対応する磁気特性の変動が確認された。都市部の樹木の葉に吸着された自動車のエンジンや工場などに起因する磁性微粒子の研究は多くされているが、樹幹の年輪に対応する磁気特性の年単位・季節単位変動の研究は初めてであり、SQUID磁気顕微鏡による高感度・高分解能分析で初めて明らかとなった。磁気シグナルが春目部分に見られること、赤茶色の斑点に対応することについて、赤松に特有の現象であるのか、自然現象であるのか、都市部の環境に関連するのか、そのメカニズムの解明が今後の課題である。
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Report
(4 results)
Research Products
(35 results)
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[Journal Article] Scanning SQUID microscope system for geological samples: system integration and initial evaluation2016
Author(s)
H. Oda, J. Kawai, M. Miyamoto, I. Miyagi, M. Sato, A. Noguchi, Y. Yamamoto, J. Fujihira, N. Natsuhara, Y. Aramaki, T. Masuda, C. Xuan
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Journal Title
Earth Planets Space
Volume: 68
Issue: 1
DOI
Related Report
Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
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[Journal Article] SQUID Microscope with Hollow-Structured Cryostat for Magnetic Field Imaging of Room Temperature Samples2016
Author(s)
Kawai, J., Oda, H., Fujihira, J.,Miyamoto, M., Miyagi, I., Sato. M.
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Journal Title
IEEE Transactions on Applied Superconductivity
Volume: 26
Issue: 5
Pages: 1600905-1600905
DOI
Related Report
Peer Reviewed
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