Higginson, Matthew J. and Altabet, Mark A. (2001): Millennial-scale fluctuations in stable isotope and productivity proxy records in the N. South China Sea during the last glacial-interglacial cycle; comparison between the East Asian monsoon and south west monsoon

Leg/Site/Hole:
ODP 184
ODP 184 1144
Identifier:
2002-064049
georefid

Creator:
Higginson, Matthew J.
University of Massachusetts at Dartmouth, School for Marine Science and Technology, New Bedford, MA, United States
author

Altabet, Mark A.
author

Identification:
Millennial-scale fluctuations in stable isotope and productivity proxy records in the N. South China Sea during the last glacial-interglacial cycle; comparison between the East Asian monsoon and south west monsoon
2001
In: Anonymous, Geological Society of America, 2001 annual meeting
Geological Society of America (GSA), Boulder, CO, United States
33
6
224
Several published records attest to the response of the mid- and low-latitudes to millennial-scale climatic variability. However, forcings, teleconnections and relative leads/lags between the sub-tropics and polar latitudes remain unclear. We focus on the biological response to fluctuations in East Asian Monsoon intensity on sub-millennial timescales in the South China Sea (SCS) and compare these records with those obtained from the NW Arabian Sea dominated by the SW Monsoon. We have analyzed very rapidly accumulating sediments (c. 50 cm/Ka) from the northern SCS recovered during ODP Leg 184 (Site 1144) in a region of high surface productivity c. 400 km SE of Hong Kong. The SCS is the largest semi-enclosed marginal basin of the W. Pacific and is especially sensitive to the influences of the West Pacific Warm Pool and East Asian Monsoon. Nutrient supply from upwelling during the winter monsoon is augmented by cyclonic advection of substantial areas of remotely-forced upwelled water with a high nutrient content both offshore NW Philippines and SW of Taiwan during prevailing NE winds. With temporal resolution <100 yr, our results exhibit millennial-scale variations in both stable isotopes (Nitrogen and Oxygen) and productivity proxies (Chlorins, total N) with evident correlation to the oxygen isotopic record of D-O events from the GISP2 ice-core. Apparently rapid and abrupt increases in productivity record intensification of the winter monsoon during cold periods, whilst remote changes in W. Pacific intermediate source water without the SCS basin appear to control sedimentary isotopic composition. Comparison with similar records in the NW Arabian Sea under the influence of the SW summer monsoon facilitates analysis of the response of the monsoon system to changes in vegetation, albedo and pressure gradient over the Himalayan-Tibetan Plateau (HTP). Monsoon intensity is clearly tightly coupled to high latitude climate change. Variations in seasonal response on the HTP produce quite different responses in areas affected by the two monsoon systems, with important regional feedback effects. Non-concordant variations in winter and summer monsoon intensity respectively offer an intriguing insight into the most likely processes connecting the monsoon system to global records of rapid climate change.
English
Coverage:Geographic coordinates:
North:20.0311
West:117.2508East: 117.2508
South:20.0311

Quaternary geology; Isotope geochemistry; Cenozoic; chemical composition; climate change; Holocene; Leg 184; marine sediments; monsoons; North Pacific; Northwest Pacific; Ocean Drilling Program; ODP Site 1144; Pacific Ocean; paleoclimatology; paleoecology; productivity; Quaternary; sediments; South China Sea; upper Holocene; West Pacific;

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