[M-IS05] 南大洋・南極氷床が駆動する全球気候変動

[MIS05-P05] 東南極スカルブスネス露岩域における小氷期以降の環境変遷

*香月 興太¹、鎌田 唯斗²、若林 繁命²、川岸 萌瑛美²、辻本 彰⁶、菅沼 悠介³、柴田 大輔⁴、川又 基人⁵ (1.島根大学エスチュアリー研究センター、2.島根大学総合理工学部、3.国立極地研究所、4.筑波大学下田臨海実験センター、5.総合研究大学院大学、6.島根大学教育学部)

キーワード：南極、露岩域、珪藻、古環境

Recently, there has been concern over the rapid melting of the Antarctic ice sheet due to increases in air and sea temperatures. Then, researches about instrumental and satellite ice sheet and ocean observations have been eagerly studied in recent. Furthermore, geological research for understanding the ice sheet melting history since the last glacial maximum has also been actively. On the other hand, unfortunately, there has been little research on the history of ice sheet changes and its effect on Antarctic lake ecosystems over the past few hundred years, when the effects of anthropogenic warming have become more pronounced. Therefore, we investigate the changes of Antarctic lake ecosystem since the little ice age based on the lowland and glacial lakes which may have the relatively high sedimentation rate. It is well used diatom remains for reconstructing the paleo lake ecosystem and environment. In Antarctic region, diatom distributions and ecology were reported from the fresh water and saline lake in ice free areas and outer sea, however it was rare reports for coast and gulf. In this study, the diatom distributions along the coast of Gulfs of Osen and Torinosu in Skalvsnes were investigated at first, then the diatom remains in sediment of the small lakes along the Gulf of Osen was analyzed. Skalvsnes is the one of the ice free area along the Soya Coast in East Antarctica. Lake Koike is the small fresh water lake, and fresh water diatom taxa has been dominated in the sediment. The number of diatom valves in the sediment has been highly fluctuated, and the peaks of diatom valves occur when the marine diatom increased. It probably means that the austral summer high tide event has been occurred in cyclic.