[M-IS03] アジア・モンスーンの進化と変動，新生代全球気候変化におけるモンスーンの位置づけ

[MIS03-P06] Amplitude modulation of sea surface temperature variability in the Bay of Bengal by 400-kyr eccentricity cycle

*山本 正伸¹、土屋 優子¹、Steven Clemens² (1.北海道大学大学院地球環境科学研究院、2.ブラウン大学地球惑星環境科学科)

キーワード：ベンガル湾、水温、中期更新世遷移期

We generated a 1.7 kyr-resolution TEX₈₆-based sea surface temperature (SST) record from the International Ocean Discovery Program Site U1446 in the Bay of Bengal during the last 1.46 Myr. The SST varied synchronously with LR04 benthic foraminifera δ¹⁸O and deep water δ¹³C. The cyclicity changed from 41-kyr to 100-kyr around 900 ka. The amplitude of SST variation responded to the 400-kyr cycles of eccentricity. Higher amplitude corresponded to low eccentricity. This suggests that eccentricity forced climate variability independently of the shift of cyclicity of glacial cycles across the Mid-Pleistocene Transition.