Fractionation of O 2 ∕N 2 and Ar∕N 2 in the Antarctic ice sheet during bubble formation and bubble–clathrate hydrate transition from precise gas measurements of the Dome Fuji ice core

• Published in: The Cryosphere
• Main Authors: I. Oyabu, K. Kawamura, T. Uchida, S. Fujita, K. Kitamura, M. Hirabayashi, S. Aoki, S. Morimoto, T. Nakazawa, J. P. Severinghaus, J. D. Morgan
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2021
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; Antarctic; The Antarctic; Dome Fuji; Antarc*; ice core; Ice Sheet; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-15-5529-2021; https://doaj.org/article/d0059c1a940546db8ff04f38ad24d920

The variations of <math xmlns="http://www.w3.org/1998/Math/MathML" id="M5" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="italic">δ</mi><msub><mi mathvariant="normal">O</mi><mn mathvariant="normal">2</mn></msub><mo>/</mo><msub><mi mathvariant="normal">N</mi><mn mathvariant="normal">2</mn></msub></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="41pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="816dbf852a36c410d98219a7c59262d8"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-15-5529-2021-ie00007.svg" width="41pt" height="14pt" src="tc-15-5529-2021-ie00007.png"/></svg:svg> and <math xmlns="http://www.w3.org/1998/Math/MathML" id="M6" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="italic">δ</mi><mi mathvariant="normal">Ar</mi><mo>/</mo><msub><mi mathvariant="normal">N</mi><mn mathvariant="normal">2</mn></msub></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="39pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="57ca8d874fcc8b04e3df557bec890511"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-15-5529-2021-ie00008.svg" width="39pt" height="14pt" src="tc-15-5529-2021-ie00008.png"/></svg:svg> in the Dome Fuji ice core were measured from 112 m (bubbly ice) to 2001 m (clathrate hydrate ice). Our method, combined with the low storage temperature of the samples ( −50 ∘ C), successfully excludes post-coring gas-loss fractionation signals from our data. From the bubbly ice to the middle of the bubble–clathrate transition zone (BCTZ) (112–800 m) and below the BCTZ ( >1200 m), the <math xmlns="http://www.w3.org/1998/Math/MathML" id="M10" display="inline" overflow="scroll" ...