Sano
Yuji
Sano
Yuji
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ArticleA comprehensive global oceanic dataset of helium isotope and tritium measurements.(Copernicus Publications, 2019-04-05) Jenkins, William J. ; Doney, Scott C. ; Fendrock, Michaela ; Fine, Rana A. ; Gamo, Toshitaka ; Jean-Baptiste, Philippe ; Key, Robert M. ; Klein, Birgit ; Lupton, John E. ; Newton, Robert ; Rhein, Monika ; Roether, Wolfgang ; Sano, Yuji ; Schlitzer, Reiner ; Schlosser, Peter ; Swift, James H.Tritium and helium isotope data provide key information on ocean circulation, ventilation, and mixing, as well as the rates of biogeochemical processes and deep-ocean hydrothermal processes. We present here global oceanic datasets of tritium and helium isotope measurements made by numerous researchers and laboratories over a period exceeding 60 years. The dataset's DOI is https://doi.org/10.25921/c1sn-9631, and the data are available at https://www.nodc.noaa.gov/ocads/data/0176626.xml (last access: 15 March 2019) or alternately http://odv.awi.de/data/ocean/jenkins-tritium-helium-data-compilation/ (last access: 13 March 2019) and includes approximately 60 000 valid tritium measurements, 63 000 valid helium isotope determinations, 57 000 dissolved helium concentrations, and 34 000 dissolved neon concentrations. Some quality control has been applied in that questionable data have been flagged and clearly compromised data excluded entirely. Appropriate metadata have been included, including geographic location, date, and sample depth. When available, we include water temperature, salinity, and dissolved oxygen. Data quality flags and data originator information (including methodology) are also included. This paper provides an introduction to the dataset along with some discussion of its broader qualities and graphics.
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ArticleLinking deeply-sourced volatile emissions to plateau growth dynamics in southeastern Tibetan Plateau(Nature Research, 2021-07-06) Zhang, Maoliang ; Guo, Zhengfu ; Xu, Sheng ; Barry, Peter H. ; Sano, Yuji ; Zhang, Lihong ; Halldórsson, Saemundur ; Chen, Ai-Ti ; Cheng, Zhihui ; Liu, Cong-Qiang ; Li, Si-Liang ; Lang, Yun-Chao ; Zheng, Guodong ; Li, Zhongping ; Li, Liwu ; Li, YingThe episodic growth of high-elevation orogenic plateaux is controlled by a series of geodynamic processes. However, determining the underlying mechanisms that drive plateau growth dynamics over geological history and constraining the depths at which growth originates, remains challenging. Here we present He-CO2-N2 systematics of hydrothermal fluids that reveal the existence of a lithospheric-scale fault system in the southeastern Tibetan Plateau, whereby multi-stage plateau growth occurred in the geological past and continues to the present. He isotopes provide unambiguous evidence for the involvement of mantle-scale dynamics in lateral expansion and localized surface uplift of the Tibetan Plateau. The excellent correlation between 3He/4He values and strain rates, along the strike of Indian indentation into Asia, suggests non-uniform distribution of stresses between the plateau boundary and interior, which modulate southeastward growth of the Tibetan Plateau within the context of India-Asia convergence. Our results demonstrate that deeply-sourced volatile geochemistry can be used to constrain deep dynamic processes involved in orogenic plateau growth.
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ArticleIntracellular isotope localization in Ammonia sp. (Foraminifera) of oxygen-depleted environments : results of nitrate and sulfate labeling experiments(Frontiers Media, 2016-02-19) Nomaki, Hidetaka ; Bernhard, Joan M. ; Ishida, Akizumi ; Tsuchiya, Masashi ; Uematsu, Katsuyuki ; Tame, Akihiro ; Kitahashi, Tomo ; Takahata, Naoto ; Sano, Yuji ; Toyofuku, TakashiSome benthic foraminiferal species are reportedly capable of nitrate storage and denitrification, however, little is known about nitrate incorporation and subsequent utilization of nitrate within their cell. In this study, we investigated where and how much 15N or 34S were assimilated into foraminiferal cells or possible endobionts after incubation with isotopically labeled nitrate and sulfate in dysoxic or anoxic conditions. After 2 weeks of incubation, foraminiferal specimens were fixed and prepared for Transmission Electron Microscopy (TEM) and correlative nanometer-scale secondary ion mass spectrometry (NanoSIMS) analyses. TEM observations revealed that there were characteristic ultrastructural features typically near the cell periphery in the youngest two or three chambers of the foraminifera exposed to anoxic conditions. These structures, which are electron dense and ~200–500 nm in diameter and co-occurred with possible endobionts, were labeled with 15N originated from 15N-labeled nitrate under anoxia and were labeled with both 15N and 34S under dysoxia. The labeling with 15N was more apparent in specimens from the dysoxic incubation, suggesting higher foraminiferal activity or increased availability of the label during exposure to oxygen depletion than to anoxia. Our results suggest that the electron dense bodies in Ammonia sp. play a significant role in nitrate incorporation and/or subsequent nitrogen assimilation during exposure to dysoxic to anoxic conditions.