[M-IS12] 古気候・古海洋変動

[MIS12-P17] 過去5万年間のベーリング海南部の1000年スケール変動

*岡崎 裕典¹、朝日 博史²、岩崎 晋弥³、久保田 瑠珂¹、高橋 孝三¹ (1.九州大学大学院理学研究院地球惑星科学部門、2.福井県里山里海湖研究所、3.北海道大学大学院環境科学院)

キーワード：ベーリング海、最終氷期、1000年スケール変動

We present downcore profiles of the multi-proxy records in a piston core BOW-9A from the Bowers Ridge at 2400 m water depth in the southern Bering Sea obtained during KH99-3 cruise by R/V Hakuho-maru in the summer of 1999. The age model of BOW-9A was established by radiocarbon dates of planktic foraminifera, benthic foraminiferal oxygen isotope stratigraphy, and paleointensity. Millennial-scale oscillations were found in the CaCO3 contents and planktic foraminiferal isotope records during the marine isotope stage (MIS) 3. The number of the CaCO3 peaks was much smaller than the Dansgaard-Oeschger events (D-O events), perhaps corresponding to the long interstadials such as D-O events 8, 12, and 14. Similar patterns in CaCO3 contents were also reported in the northern Bering Sea. Biogenic opal contents during MIS 3 ranged from 20 to 50 wt%, comparable to those during MIS 1.