EGU22-6818, updated on 28 Mar 2022
https://doi.org/10.5194/egusphere-egu22-6818
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Chronostratigraphy of Larsen blue ice, East Antarctica, and a tentative reconstruction of surface temperature and accumulation rate during the last deglaciation

Giyoon Lee1, Jinho Ahn1, Hyeontae Ju2, Florian Ritterbusch3, Ikumi Oyabu4, Christo Buizert7, Songyi Kim2, Jangil Moon2, Sambit Ghosh1, Kenji Kawamura4,5,6, Zheng-Tian Lu3, Sangbum Hong2, Chang Hee Han2, Soon Do Hur2, Wei Jiang3, and Guo-Min Yang3
Giyoon Lee et al.
  • 1School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea
  • 2Korea Polar Research Institute, Incheon, South Korea
  • 3Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
  • 4National Institute of Polar Research, Tachikawa, Japan
  • 5Department of Polar Science, School of Multidisciplinary Sciences, The Graduate University for Advanced Studies, SOKENDAI, Tachikawa, Japan
  • 6Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
  • 7College of Earth, Ocean and Atmospheric Sciences, Oregon State University (OSU), Corvallis, OR, USA

Ice coring in blue ice areas (BIAs) serves as an alternative to deep ice core drilling, allowing collection of large-sized old ice samples in a cost-effective way because old ice samples are outcropped to the surface. However, the stratigraphy in many blue ice areas can be complicated due to complex ice flows. Based on ice layers defined by dust bands and ground penetration radar (GPR) surveys, we show that Larsen BIA has a surface transect of ice with an undisturbed horizontal stratigraphy from mid- to downstream side ice. However, the upstream ice exhibits a potential repetition of ages on scales of tens of meters. Correlating δ18Oice, δ18Oatm, and CH­4 records of Larsen ice with existing ice core records indicates that the analyzed gas age and ice age ranges between 9.2–23.4 ka BP and 5.6–24.7 ka BP, respectively. Radiometric 81Kr dating of one of the cores confirms the estimated gas ages within uncertainty. A tentative reconstruction based on a simple analytical framework suggests a warming of 15 ± 5 ℃ during the last deglaciation that we attribute to the retreat of the Ross Ice Shelf, and an increase in snow accumulation by a factor of 1.7–4.6 that we attribute to the increased penetration of snow-bearing storms. Exact estimation of the original deposition site and updated ice ages may enhance the tentative climate reconstructions in future studies. Our study shows that BIAs in Northern Victoria Land may contribute to obtain high-quality paleoclimate proxy records through the last deglaciation.

How to cite: Lee, G., Ahn, J., Ju, H., Ritterbusch, F., Oyabu, I., Buizert, C., Kim, S., Moon, J., Ghosh, S., Kawamura, K., Lu, Z.-T., Hong, S., Han, C. H., Hur, S. D., Jiang, W., and Yang, G.-M.: Chronostratigraphy of Larsen blue ice, East Antarctica, and a tentative reconstruction of surface temperature and accumulation rate during the last deglaciation, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6818, https://doi.org/10.5194/egusphere-egu22-6818, 2022.

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