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DOI	10.1016/j.epsl.2021.117119
	A tephra-based approach to calibrating relative geomagnetic paleointensity stacks to absolute values
	Mochizuki N.; Fujii S.; Hasegawa T.; Yamamoto Y.; Hatakeyama T.; Yamashita D.; Okada M.; Shibuya H.
发表日期	2021
ISSN	0012821X
卷号	572
英文摘要	Relative paleointensity (RPI) stacks provide a relative, global paleointensity variation, which reflects variations in the geocentric axial dipole moment. Previous calibrations of an RPI stack rely on adjusting a mean RPI to a mean of virtual axial dipole moments (VADMs), which are selected from absolute paleointensity (API) databases. To achieve more quantitative calibration of an RPI stack into absolute values, we propose a novel approach that compares (1) tephra-derived APIs and (2) the same tephras' horizons, in the oxygen isotope stratigraphy, tied RPIs (hereafter termed the “TA-TOR” approach). For the TA-TOR approach, APIs were newly determined for welded tuffs of 15 pyroclastic flow deposits in Japan. Eight of the 15 new APIs and 2 previously reported APIs have tephra horizons in the oxygen isotope stratigraphy. Based on the 10 data of the TA-TOR approach, combined with 4 data of the transitional field, VADMs calculated from the APIs (VADMAPI) were compared with isochronous RPIs from two RPI stacks, PISO-1500 and Sint-2000. The 14 data points in RPI vs. VADMAPI diagrams show a linear relationship with correlation coefficients of 0.83–0.89. Using the observed linear relationships, the two RPI stacks were reliably calibrated to VADM values (VADMRPI) for the period since 1.1 Ma. Compared with the VADMs calibrated by the previous studies, the present calibration provides a 12–13% smaller median/mean and a larger dispersion as represented by a 15–53% larger standard deviation for the two RPI stacks. The similarities between the cumulative distributions of VADMRPI from the two stacks and those of VADMs selected from the API database indicate the reliability of the present calibration. These results show that the present calibration, which relies on the TA-TOR approach, accurately converts a RPI stack into VADMRPI values and will contribute to studies on time variations in the geocentric axial dipole moment, sedimentary RPI, and cosmogenic radionuclides. Variations in VADMRPI for the past 1.1 Myr, obtained from PISO-1500 and Sint-2000 via the present calibration, can be used as standard geocentric axial dipole variations for this period. © 2021 Elsevier B.V.
关键词	absolute paleointensity calibration oxygen isotope stratigraphy relative paleointensity tephra welded tuff
英文关键词	Geomagnetism; Isotopes; Oxygen; Stratigraphy; Welding; Absolute paleointensity; Absolute values; Axial dipole; Geomagnetics; Linear relationships; Oxygen isotope stratigraphy; Paleo-intensities; Relative paleointensity; Tephrum; Welded tuff; Calibration
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203226
作者单位	Department of Earth and Environmental Sciences, Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan; Department of Earth and Environmental Sciences, Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan; Department of Earth Sciences, College of Science, Ibaraki University, Mito, 310-8512, Japan; Center for Advanced Marine Core Research, Kochi University, Kochi, 783-8502, Japan; Institute of Frontier Science and Technology, Okayama University of Science, Okayama, 700-0005, Japan; Satsumasendai City Office, Satsumasendai, 896-1392, Japan; Research Center for Knowledge Science in Cultural Heritage, Doshisya University, Kyotanabe, 610-0394, Japan
推荐引用方式 GB/T 7714	Mochizuki N.,Fujii S.,Hasegawa T.,et al. A tephra-based approach to calibrating relative geomagnetic paleointensity stacks to absolute values[J],2021,572.
APA	Mochizuki N..,Fujii S..,Hasegawa T..,Yamamoto Y..,Hatakeyama T..,...&Shibuya H..(2021).A tephra-based approach to calibrating relative geomagnetic paleointensity stacks to absolute values.Earth and Planetary Science Letters,572.
MLA	Mochizuki N.,et al."A tephra-based approach to calibrating relative geomagnetic paleointensity stacks to absolute values".Earth and Planetary Science Letters 572(2021).