[U-03] Advanced understanding of Quaternary and Anthropocene hydroclimate changes in East Asia

[U03-01] 別府湾堆積物における人為痕跡数の急激な増加が人新世の始まりの明確な指標となる

★招待講演

*加 三千宣¹、Finney Bruce²、Shi Zhiyuan ³、坂口 綾³、槻木 玲美⁴、大森 貴之⁵、阿草 哲郎⁶、鈴木 克明⁷、横山 祐典⁵、日向 博文¹、畑田 佳男¹、井上 淳⁸、松岡 數充⁹、嶋田 美咲¹⁰、高原 光¹⁰、高橋 真¹、上野 大介¹¹、天野 敦子⁷、堤 純³、山本 正伸¹²、竹村 恵二¹³、山田 圭太郎¹⁴、池原 研⁷、原口 強¹⁵、Tims Stephen ¹⁶、Froehlich Michaela ¹⁶、Fifield Keith¹⁶、阿瀬 貴博⁵、笹 公和³、高橋 努⁵、松村 万寿美³、谷 幸則¹⁷、Leavitt Peter ¹⁸、土居 秀幸¹³、入野 智久¹²、守屋 和佳¹⁹、林田 明²⁰、廣瀬 孝太郎²¹、鈴木 秀和²²、齋藤 文紀²³ (1.愛媛大学、2.アイダホ州立大学、3.筑波大学、4.松山大学、5.東京大学、6.熊本県立大学、7.産業技術総合研究所、8.大阪公立大学、9.長崎大学、10.京都府立大学、11.佐賀大学、12.北海道大学、13.京都大学、14.立命館大学、15.大阪市立大学、16.オーストラリア国立大学、17.静岡県立大学、18.レジャイナ大学、19.早稲田大学、20.同志社大学、21.兵庫県立大学、22.東京海洋大学、23.島根大学)

キーワード：人新世、GSSP、別府湾、人為痕跡、グレートアクセラレーション

‘Great Acceleration’ has been a convincing rationale of the start of an Anthropocene epoch because of the intensity, magnitude, planetary significance, and global isochroneity (Waters et al., 2022). While there are diverse proxy records that support impacts of the Great Acceleration on the geological environments around the mid-20th century, they show diachronous timings not only between the different proxy-based anthropogenic events but also between sites for the same proxy. Therefore, the onset of the Great Acceleration seen in the geological strata still remains to be well-defined. It also remains unclear whether or not a rapid increase in plutonium, which is considered a primary marker of the start of the Anthropocene, is consistent with a geological marker of the onset of the Great Acceleration. Here we present cumulative numbers of the anthropogenic fingerprints in the Beppu Bay sediments, which were detected from 57 proxies (Kuwae et al., 2022). An explosion of the number of fingerprints in the Beppu Bay stratigraphy could detect the impacts of intensified human activities on the geological environments and produce a simple and reasonable geological marker of the onset of the Great Acceleration. An explosion of the anthropogenic fingerprints was detected at the 1953 CE level (64.6 cm depth in the master core, a candidate for the Anthropocene GSSP), at which radioactivity of ^239+240Pu starts abruptly increasing (Kuwae et al., 2022). This result supports that the plutonium signature is suitable as the onset of the Great Acceleration and the Anthropocene.

References
Kuwae, M., Finney, B., Shi, Z., Sakaguchi, A., Tsugeki, N., Omori, T., Agusa, T., Suzuki, Y., Yokoyama, Y., Hinata, H., Hatada, Y., Inoue, J., Matsuoka, K., Shimada, M., Takahara, H., Takahashi, S., Ueno, D., Amano, A., Tsutsumi, J., Yamamoto, M., Takemura, K., Yamada, K., Ikehara, K., Haraguchi, T., Tims, S., Froehlich, M., Fifield, L.K., Aze, T., Matsumura, M., Takahashi, T., Sasa, K., Tani, Y., Leavitt, P.R., Doi, H., Irino, T., Moriya, K., Hayashida, A., Hirose, K., Suzuki, H. and Saito, Y. (2022) Beppu Bay, Japan, as a candidate Global boundary Stratotype Section and Point for the Anthropocene series. The Anthropocene Review. https://doi.org/10.1177/20530196221135077
Waters, C.N., Williams, M., Zalasiewicz, J., Turner, S.D., Barnosky, A.D., Head, M.J., Wing, S.L., Wagreich, M., Steffen, W., Summerhayes, C.P., Cundy, A.B., Zinke, J., Fiałkiewicz-Kozieł, B., Leinfelder, R., Haff, P.K., McNeill, J.R., Rose, N.L., Hajdas, I., McCarthy, F.M.G., Cearreta, A., Gałuszka, A., Syvitski, J., Han, Y., An, Z., Fairchild, I.J., Ivar do Sul, J.A. and Jeandel, C. (2022) Epochs, events and episodes: Marking the geological impact of humans. Earth-Science Reviews 234:104171.