HR: 0830h
AN: OS41C-0814    [PDF]
TI: Fluctuations of the cold Oyashio Current front off NE Japan in the last 100 ka
AU: * Huang, C
EM: huangcy@mail.ncku.edu.tw
AF: Department of Earth Sciences, National Cheng Kung University, Tainan, TWN 701 Taiwan
AU: Chen, J
EM: L4689115@ccmail.ncku.edu.tw
AF: Department of Earth Sciences, National Cheng Kung University, Tainan, TWN 701 Taiwan
AU: Huang, C
EM:
AF: Department of Earth Sciences, National Cheng Kung University, Tainan, TWN 701 Taiwan
AU: Zhao, M
EM: meixun.Zhao@Dartmouth.Edu
AF: Department of Earth Sciences, National Cheng Kung University, Tainan, TWN 701 Taiwan
AU: Zhao, M
EM: meixun.Zhao@Dartmouth.Edu
AF: Department of Earth Sciences, Dartmouth College, Hanover, NH 03755-3571 United States
AB: Millennial-scale alkenone sea surface temperature (UK37 SST) and planktic foraminifer records of IMAGES core MD012419 (38o53.02'N, 143o19.46'E, water depth 2291 m) indicate that the cold Oyahio Current front off NE Japan fluctuated remarkably in the last 100 Ka. The SST record indicates glacial-interglacial changes of 6oC with smaller millennial-scale changes, and these changes are attributed to the interaction of the warm Kuroshio Current and the cold Oyahio Current. Planktic foraminifers of warm water assemblage (P. obliqueloculata, G. menardii and G. sacculifer) appeared in MIS5 when SST was the highest (18.5-20oC), suggesting the Kuroshio Current might have extended northward 3oN higher than today (35oN). Abundant N. pachyderma (left), a characteristic Oyashio Current species for this region, occurred in LGM and Termination I when SST was low (12-15oC). However, temperate water fauna predominated by G. inflata and G. bulloides was found in the Holocene and MIS3\&4, suggesting an oceanographic condition similar to today's Perturbed area off NE Japan. In addition, oxygen isotope record of G. inflata indicates salinity might also play an important role in response to paleoceangraphic changes. When UK37 SST increased from MIS 4 (13oC) to MIS 3 (17.5oC), the increasing oxygen isotope of G. inflata suggests the saline Kuroshio water might have mixed with the low salinity Oyashio Water, consistent with planktic foraminiferal data.
DE: 1600 GLOBAL CHANGE (New category)
DE: 4243 Marginal and semienclosed seas
DE: 4267 Paleoceanography
DE: 4283 Water masses
DE: 4576 Western boundary currents
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting