JpGU-AGU Joint Meeting 2020

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[E] Oral

U (Union ) » Union

[U-05] Advanced understanding of Quaternary and Anthropocene hydroclimate changes in East Asia

convener:Chuan-Chou Shen(High-Precision Mass Spectrometry and Environment Change Laboratory, Department of Geosciences, National Taiwan University), Yusuke Yokoyama(Atmosphere and Ocean Research Institute, University of Tokyo), Kaoru Kubota(Graduate School of Human Development and Environment, Kobe University), Li Lo(Department of Geosciences, National Taiwan University), Chairperson:Chuan-Chou Shen(High-Precision Mass Spectrometry and Environment Change Laboratory, Department of Geosciences, National Taiwan University), Chairperson:Yusuke Yokoyama(Atmosphere and Ocean Research Institute, University of Tokyo), Chairperson:Kaoru Kubota(Kochi Institute for Core Sample Research, JAMSTEC), Chairperson:Li Lo(Department of Geosciences, National Taiwan University)

[U05-06] Benthic biotic response to Quaternary climate changes in the Sea of Japan and other Asian regions

★Invited Papers

*Moriaki Yasuhara1 (1.University of Hong Kong)

The Sea of Japan is a marginal sea, connecting to adjacent seas by four shallow straits (water depths <130 m). Marginal seas are ideal for studying biotic responses to large-scale environmental changes as they often are sensitive to glacial-interglacial and stadial-interstadial climatic cycles. However, only a limited number of studies cover time periods beyond the last two glacial-interglacial cycles. In this presentation, I will show long Quaternary records of benthic biotic response to paleoceanographic changes in the southern Sea of Japan, covering many glacial-interglacial cycles, based on ostracode assemblages at the Integrated Ocean Drilling Program (IODP) Site U1427 and U1426. The results indicate that orbital-scale oxygen variability in the bottom water has been the major control impacting the marginal-sea biota, and secular-scale faunal transitions are likely associated with the mid-Brunhes event (∼0.43 Ma) and the onset of the Tsushima Warm Current (∼1.7 Ma). Benthic ecosystems in marginal seas are sensitive and vulnerable to both short- and long-term climatic changes, and the mid-Brunhes event is suggested to be a global biotic event affecting benthic ecosystems substantially. I will also introduce other recent examples of Asian biotic response studies.