Changes in surface water masses in the northern East China Sea since the Last Glacial Maximum based on diatom assemblages

Progress in Earth and Planetary Science

Yosuke Miyairi¹  Yusuke Yokoyama²  Yusuke Okazaki³  Keiko Shirota³  Susumu Konno⁴  Yoshimi Kubota⁵ 

[1] Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, 277-8564, Kashiwa, Chiba, Japan;Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, 277-8564, Kashiwa, Chiba, Japan;Department of Earth and Planetary Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-0033, Tokyo, Japan;Graduate Program Onn Environmental Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, 153-8902, Tokyo, Japan;Biogeochemistry Research Center, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, 237-0061, Yokosuka, Japan;Research School of Physics, The Australian National University, 2601, Canberra, ACT, Australia;Department of Earth and Planetary Sciences, Graduate School of Science, Kyushu University, 744 Motooka, Nishi-ku, 819-0395, Fukuoka, Japan;Marine Works Japan Ltd, 2-15 Natsushima-cho, 237-0061, Yokosuka, Japan;National Museum of Nature and Science, 4-1-1, Amakubo, 305-0005, Tsukuba, Ibaraki, Japan;

关键词: Diatoms;    East China Sea;    Sediment core;    Last Glacial Maximum;    Holocene;    Water mass;    Chinese coastal water;    Kuroshio;   

DOI  :  10.1186/s40645-021-00456-1

来源: Springer

【 摘 要 】

We investigated diatom assemblages for the last 19 ka in a piston core KY07-04 PC01 collected from the northern Okinawa Trough, East China Sea. Most of the diatom taxa in the Core KY07-04 PC01 were subtropical to temperate marine species throughout the core. Pronounced turnover of major diatom groups from periphytic to planktonic taxa occurred during deglaciation between 17 and 14 ka ago. During the Last Glacial Maximum (LGM) to early deglaciation, the representative taxa were Paralia spp., a periphytic diatom abundant in continental shelves of the modern East China Sea covering the Chinese Coastal Water. Relative abundances of Paralia spp. rapidly decreased during 15–14 ka ago, corresponding to sea-level rise, displaced by planktonic taxa such as Thalassionema. Thalassionema nitzschioides varieties living in subtropical water increased since 12 ka and have reached the present level at 8 ka ago, suggesting strengthening the influences of Kuroshio water in the northern East China Sea during the early to middle Holocene. Warm planktonic diatom taxa such as Nitzschia bicapitata also gradually increased from 12 to 8 ka ago. Near the core top, a sudden increase in N. bicapitata might relate to the intensifying Kuroshio during the latest Holocene.

【 授权许可】

CC BY