Isotopic signature of massive, buried ice in eastern Taylor Valley, Antarctica: Implications for its origin

• Published in: Arctic, Antarctic, and Alpine Research
• Main Authors: Christopher B. Gardner, Melisa A. Diaz, Devin F. Smith, Andrew G. Fountain, Joseph S. Levy, W. Berry Lyons
• Format: Article in Journal/Newspaper
• Language: English
• Published: Taylor & Francis Group 2022
• Subjects: Buried ice; McMurdo Dry Valleys; Last Glacial Maximum; ice-cored moraine; geo; envir; Antarctic; Ross Sea; Taylor Valley; West Antarctic Ice Sheet; Antarc*; Antarctic and Alpine Research; Antarctica; Arctic; Ice; Ice Sheet; permafrost; Sea ice
• Online Access: https://doi.org/10.1080/15230430.2022.2102510; https://doaj.org/article/1eee5cbc68a44a60a7adb827010d7448

The coastal regions of the McMurdo Dry Valleys, Antarctica, contain deposits of the Ross Sea Drift, sedimentary material left from the Ross Sea ice sheet from the advance of the West Antarctic ice sheet during the Last Glacial Maximum. Much of this deposit is ice-cored, but data on the stable isotopic composition of water from this ice, which may contain a valuable climate archive, are sparse or incomplete. Widespread thermokarstic ground subsidence in this “coastal thaw zone” of the McMurdo Dry Valleys suggests that these potential records are rapidly being lost due to the melting of ground ice and permafrost. We collected samples of massive buried ice from the Ross Sea Drift in eastern Taylor Valley for δ18O-H2O and δ2H-H2O and measured a broad range of values (δ18O = −27.7 to −37.3 ‰; δ2H = −210 to −295 ‰). These buried ice deposits do not show evidence of alteration through sublimation or evaporation, plot along the local meteoric water line, and have values that indicate ice deposition under a colder climate than present conditions. We propose that this ice was sourced from the Ross Sea ice sheet during the Last Glacial Maximum and contains a valuable and accessible climate record.