Discovery of argon in air-hydrate crystals in a deep ice core using scanning electron microscopy and energy-dispersive X-ray spectroscopy
| Autor: | Tsutomu Uchida, Wataru Shigeyama, Ikumi Oyabu, Kumiko Goto-Azuma, Fumio Nakazawa, Tomoyuki Homma, Kenji Kawamura, Dorthe Dahl-Jensen |
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| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Journal of Glaciology, Vol 68, Pp 547-556 (2022) |
| Druh dokumentu: | article |
| ISSN: | 0022-1430 1727-5652 |
| DOI: | 10.1017/jog.2021.115 |
| Popis: | Tiny samples of ancient atmosphere in air bubbles within ice cores contain argon (Ar), which can be used to reconstruct past temperature changes. At a sufficient depth, the air bubbles are compressed by the overburden pressure under low temperature and transform into air-hydrate crystals. While the oxygen (O2) and nitrogen (N2) molecules have indeed been identified in the air-hydrate crystals with Raman spectroscopy, direct observational knowledge of the distribution of Ar at depth within ice sheet and its enclathration has been lacking. In this study, we applied scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) to five air-hydrate crystals in the Greenland NEEM ice core, finding them to contain Ar and N. Given that Ar cannot be detected by Raman spectroscopy, the method commonly used for O2 and N2, the SEM-EDS measurement method may become increasingly useful for measuring inert gases in deep ice cores. |
| Databáze: | Directory of Open Access Journals |
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