Japan Geoscience Union Meeting 2023

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[E] Oral

U (Union ) » Union

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

Thu. May 25, 2023 9:00 AM - 10:30 AM Exhibition Hall Special Setting (1) (Exhibition Hall 8, Makuhari Messe)

convener:Li Lo(Department of Geosciences, National Taiwan University), Yusuke Yokoyama(Atmosphere and Ocean Research Institute, University of Tokyo), Kaoru Kubota(Research Institute for Marine Geodynamics, Japan Agency for Marine-Earth Science and Technology), Chuan-Chou Shen(National Taiwan University), Chairperson:Kaoru Kubota(Research Institute for Marine Geodynamics, Japan Agency for Marine-Earth Science and Technology), Li Lo(Department of Geosciences, National Taiwan University), Yusuke Yokoyama(Atmosphere and Ocean Research Institute, University of Tokyo)

9:50 AM - 10:05 AM

[U03-04] Multidecadal reconstruction of mid-Holocene climate of Western Pacific based on the stalagmite fluid inclusion isotopes

★Invited Papers

*Syed Azharuddin1, Kanako Omine2, Kosuke Masaka2, Ryuji Asami3, Mahjoor Ahmad Lone4, Yu-Chen Chou4, Chuan-Chou Shen4, Ryu Uemura1 (1.Graduate School of Environmental Studies, Nagoya University, Japan, 2.Faculty of Science, University of the Ryukyus, Japan, 3.Graduate School of Science, Tohoku University, Japan, 4.High-precision mass spectrometry and environment change laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taiwan ROC)

Keywords:Stalagmite, Stable Isotopes, Fluid Inclusions, Holocene

The oxygen isotopes in speleothem carbonate (δ18Oca) have been widely used to study the past changes in monsoonal precipitation, whereas the role of calcite formation temperature remains elusive. With recent analytical advancements, the δ18Oca coupled with oxygen and hydrogen isotopes in speleothem fluid inclusions (δ18Ofi and δDfi) offer great potential for reconstructing past air temperatures. Here we present a record of δ18Ofi and δDfi analyzed in HSN1 stalagmite from Hoshino Cave at Minami-Daito Island situated in Okinawa prefecture around the Northwestern Pacific. A robust age model was established with precise U-Th ages between 6.0 to 7.4 thousand years before the present (where the present is 1950 AD). The high-growth rate of HSN1 stalagmite (180 μm/yr) enabled us to study the past changes in precipitation and temperature with a high temporal resolution. The reconstructed air temperature shows strong multidecadal variability during the mid-Holocene. We compared our results with regional and global paleo-proxy records to identify the different forcings and teleconnections. Multiproxy data show a 65-year cycle related to the variability in the Atlantic Multidecadal Oscillation (AMO) and the multidecadal AMO-Western Pacific teleconnection.