[M-IS10] 南大洋・南極氷床が駆動する全球気候変動

[MIS10-P02] Preliminary results of the JARE64 geomorphological survey in Lutzow-Holm Bay, East Antarctica

*石輪 健樹^1,2、菅沼 悠介^1,2、柴田 大輔³、梶田 展人⁴、Van Breedam Jonas⁵、Mahesh Badanal Siddaiah⁶、山縣 広和⁷、Buffoli Marina⁸、Verleyen Elie ⁸、巻 俊宏⁷、Mohan Rahul⁶、池原 実⁹ (1.国立極地研究所、2.総合研究大学院大学、3.筑波大学、4.弘前大学、5.Vrije Universiteit Brussel、6.National Centre for Polar and Ocean Research、7.東京大学、8.Universiteit Gent、9.高知大学)

キーワード：南極、湖底堆積物、海底堆積物、ROV

Global sea-level rise due to the mass loss of the East Antarctic Ice Sheet (EAIS) under anthropogenic warming is a growing concern. Therefore, assessing the response mechanisms of the EAIS to climate change is essential for improving the accuracy of future sea-level rise projections. The EAIS undergoes numerous variations over different time scales, and understanding them forms a crucial component in reconstructing past ice sheet changes from geological archives. During the 64th Japanese Antarctic Research Expedition, a geomorphological survey was conducted with the purpose of reconstructing the changes in the EAIS since the Last Interglacial period at outcrops in the Lutzow-Holm Bay, East Antarctica. Topographic and biological surveys were carried out using a Remotely Operated Vehicle (ROV) in shallow marine bays around the Ongul Islands and Langhovde, while lake surveys (taking sediment cores and water samples) were conducted at the Ongul Islands, Langhovde, Rundvågshetta, and Strandnibba. Additionally, rock samples (both bedrocks and erratics) for surface exposure dating were collected from the regions above mentioned and from Instekleppane and Okuhyouga Iwa. Sediment cores were retrieved from 27 sites, resulting in a total of 68 m of core samples. These samples were brought to Japan, and non-destructive analyses and sub-sampling were carried out at the Marine Core Research Institute, Kochi University. We noted that sediment samples from some of the lakes at the Ongul Islands, Langhovde, and Strandnibba contain glacial till sediments. Furthermore, at Rundvågshetta, where multiple sediment cores were collected at varying distances from the ice sheet margin, different depositional environments were observed depending on the location. In this presentation, the results of the ROV-based surveys and the non-destructive analyses of the sediment cores will be summarized, and our future research plans will be discussed.