Discovery of argon in air-hydrate crystals in a deep ice core using scanning electron microscopy and energy-dispersive X-ray spectroscopy
JOURNAL OF GLACIOLOGY(2022)
Abstract
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 (O-2) and nitrogen (N-2) 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 O-2 and N-2, the SEM-EDS measurement method may become increasingly useful for measuring inert gases in deep ice cores.
MoreTranslated text
Key words
Air hydrate, argon, energy-dispersive X-ray spectroscopy, NEEM ice core, scanning electron microscopy
AI Read Science
Must-Reading Tree
Example
![](https://originalfileserver.aminer.cn/sys/aminer/pubs/mrt_preview.jpeg)
Generate MRT to find the research sequence of this paper
Chat Paper
Summary is being generated by the instructions you defined