[M-IS05] 南大洋・南極氷床が駆動する全球気候変動

[MIS05-08] Paleoenvironmental reconstruction using lake sediment cores from Lake Nurume in Lützow Holm Bay

*石輪 健樹¹、徳田 悠希²、板木 拓也³、佐々木 聡史⁴、香月 興太⁴、菅沼 悠介^1,5 (1.国立極地研究所、2.鳥取環境大学、3.産業技術総合研究所、4.島根大学、5.総合研究大学院大学)

キーワード：東南極、湖沼堆積物

Lake sediment in Antarctica is a useful archive for paleoenvironmental reconstruction as sea-level and ice-sheet change. Various sediment cores have been collected from a large number of lakes in Lützow Holm Bay, East Antarctica (e.g., Takano et al., 2012; Verleryen et al., 2017; Suganuma et al., 2018; Ishiwa et al., 2020). However, the previous studies generally used one core sample for each lake in most cases, and it is necessary to proceed with an analysis of multiple core samples to reconstruct detailed environmental changes in the lake. Lake Nurume at Langhovde, Lützow Holm Bay is isolated from the sea by ~1 m sill, and a perennial snow patch is well developed in the southeast of the lake. In the geomorphological survey of the 61st Japanese Antarctic Research Expedition, we collected four sediment cores in Lake Nurume and also measured water column profiles (e.g., salinity, temperature, and turbidity) and detailed lake bathymetry (Ishiwa et al., in press). We will present preliminary results of these cores, such as radiocarbon dating, XRF, X-ray CT scanning, and microfossils analysis of the cores. Combining geological settings and obtained results in Lake Nurume provides significant insight into paleoenvironmental reconstruction around Lützow Holm Bay. Moreover, the dataset will be a valuable archive of paleoenvironmental studies using lake sediments in Antarctica.