Onset and evolution of millennial-scale variability of the Asian monsoon and its possible relation with Himalaya and Tibetan Plateau uplift; preliminary results from IODP Expedition 346

Author(s): Tada, R.; Murray, R. W.; Alvarez Zarikian, C. A.
Author Affiliation(s): Primary:
University of Tokyo, Earth and Planetary Science, Tokyo, Japan
Other:
Boston University, Boston, MA, United States
Texas A&M University, College Station, TX, United States
Volume Title: AGU 2013 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2013; American Geophysical Union 2013 fall meeting, San Francisco, CA, Dec. 9-13, 2013. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: Integrated Ocean Drilling Program (IODP) Expedition 346 (29 July - 28 September, 2013) occupied a series of sites covering a depth and latitudinal range in the Japan Sea/East Sea, as well as one site in the northern East China Sea. The overall goal of the expedition was to test the hypothesis that Pliocene-Pleistocene uplift of the Himalaya and Tibetan Plateau, and the consequent emergence of the two discrete modes of Westerly Jet circulation, caused the amplification of millennial-scale variability of the East Asian summer monsoon (EASM) and East Asian winter monsoon (EAWM) and provided teleconnection mechanism(s) for Dansgaard-Oeschger cycles. The expedition's main focus is to investigate the timing of onset of orbital- and millennial-scale variability of the EASM and EAWM and their relation with variability of Westerly Jet circulation, reconstruct orbital- and millennial-scale changes in surface and deepwater circulations and surface productivity in the Japan Sea/East Sea during at least the last 5 m.y. Another expedition goal is to reconstruct the history of the Yangtze River discharge as it reflects variation and evolution in EASM and exerts an impact on the paleoceanography of the Japan Sea/East Sea. Through these studies, we hope to examine the interrelationship among the EASM, EAWM, nature and intensity of the influx through the Tsushima Strait, the intensity of winter cooling, surface productivity, ventilation, and bottom water oxygenation in the Japan Sea/East Sea and their changes during the last 5 m.y. The latitudinal transect of the Japan Sea will help monitor the behaviors of the Westerly Jet, EAWM, and the Tsushima Warm Current. The southern part of the transect is being used to reconstruct the behavior of the Subpolar Front and examine its relationship with the Westerly Jet and sea level changes, whereas the northern part of the transect is being used to identify ice-rafted debris events and reconstruct temporal variation in its southern limit. By drilling a depth transect, we aimed to reconstruct the ventilation history of the Japan Sea/East Sea and examine the relation between ventilation and the nature of the influx through the Tsushima Strait and/or the intensity of winter cooling. Drilling in the northern part of the East China Sea is helping constrain the Yangtze River discharge history that should reflect variations in EASM intensity. Preliminary data from the expedition will be presented, in the context of new results from the first ODP/IODP cruise to return to the Japan Sea/East Sea since 1989.
Year of Publication: 2013
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Asia; Cenozoic; China; Climate change; East China Sea; Expedition 346; Far East; Himalayas; Integrated Ocean Drilling Program; Japan Sea; Marine sediments; Neogene; North Pacific; Northwest Pacific; Pacific Ocean; Paleoclimatology; Pleistocene; Pliocene; Quaternary; Sediments; Tertiary; Tibetan Plateau; Uplifts; West Pacific
Coordinates: N313700 N434600 E1390500 E1285930
Record ID: 2014062128
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