Japan Geoscience Union Meeting 2023

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[J] Oral

M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS15] Paleoclimatology and Paleoceanography

Wed. May 24, 2023 9:00 AM - 10:30 AM International Conference Room (IC) (International Conference Hall, Makuhari Messe)

convener:Yusuke Okazaki(Department of Earth and Planetary Sciences, Graduate School of Science, Kyushu University), Hitoshi Hasegawa(Faculty of Science and Technology, Kochi University), Atsuko Yamazaki(Graduate School of Environmental Studies, Nagoya University), Takashi Obase(Atmosphere and Ocean Research Institute, The University of Tokyo), Chairperson:Yusuke Okazaki(Department of Earth and Planetary Sciences, Graduate School of Science, Kyushu University)

9:00 AM - 9:23 AM

[MIS15-21] Mechanism of the large-scale ice sheet retreat revealed by land-sea seamless surveys in East Antarctica

★Invited Papers

*Yusuke Suganuma1,2 (1.National institute of Polar Research, 2.The Graduate University for Advanced Studies (SOKENDAI))

Keywords:Antarctica Ice Sheet and Southern Ocean, Large-scale ice mass loss, Lake/marine sediment, Surface exposure dating

The East Antarctic Ice Sheet (EAIS) is the largest continental ice mass on Earth. With freshwater storage equivalent to ~52.2 m of global sea level, even minor changes in ice sheet volume can strongly influence global sea level and climate dynamics. Thus, it is critical to understand its sensitivity to various forcing agents. Recent advances in satellite gravimetry and ice-sheet modeling have yielded refined estimates of EAIS mass balance and allowed for a re-examination of its response to global climatic changes. However, space-geodetic observations of ice-sheet change only extend over the last few decades. Modelling studies of ice-sheet sensitivity to atmospheric and oceanic warming and circulation and sea-level rise require well-constrained records of past ice-sheet changes for model validation and refinement. Together, these factors highlight the need for long-term (millennial-scale) glacio-geological records obtained from field-based studies. This is especially pertinent for understanding the large-scale retreat processes of the EAIS. For the last decade, our group has carried out a series of field surveys along the Dronning Maud Land, East Antarctica, to provide a better-constrained ice-sheet thinning history for the period since the Last Glacial Maximum. The ice-thinning chronology of the coastal Dronning Maud Land of the EAIS has been obtained by geomorphological survey and surface exposure dating of glacially transported rocks on inland nunataks. The detailed process of the ice sheet and ice shelf retreat along the EAIS margin has also been reconstructed by the marine-lake sedimentary records obtained by a newly developed sediment coring system and gravity coring from the ice breaker SHIRASE. In this talk, I will introduce an overview of these activities done by our group and their outcomes.