A hydroclimate regime shift around 270 ka in the western tropical Pacific inferred from a late Quaternary n-alkane chain-length record

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doi: 10.1016/j.palaeo.2015.03.025
Author(s): Li Li; Li Qianyu; Li Jianru; Wang Hui; Dong Liang; Huang, Yongsong; Wang Pinxian
Author Affiliation(s): Primary:
Tongji University, Laboratory of Marine Geology, Shanghai, China
Other:
Brown University, United States
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Vol.427, p.79-88. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 84 refs.; illus., incl. sketch maps
Summary: The inert leaf wax deposited in deep sea sediment preserves clues of the past climate change. In particular, the n-alkane distribution patterns characterized by the n-alkane average chain length index (ACL) provide useful information on the hydrological changes, as longer chain alkanes are more frequently biosynthesized under relatively arid condition to prevent water loss. Our data from the western South China Sea reveal the superimposition of a systematic regime shift in the regional mean precipitation at ca. 420-270 ka on the glacial-interglacial changes in the Quaternary. The dominance of shorter n-alkane chain length between 420 ka and 270 ka is interpreted as overall wetter conditions during this period compared to the older or younger intervals. A similar timing of hydrological regime shifts has also been observed in other paleoclimate records, including major changes in productivity in the eastern Pacific and pollen records from the western Pacific. We suggest that the changes in the regional mean hydroclimate states near 420 ka and 270 ka are most likely related to a regime change in the frequency and/or intensity of the El Nino-Southern Oscillation, with the overall wetter hydroclimate prior to 270 ka resulting in a more prevalent La Nina-like condition in the Pacific. Abstract Copyright (2015) Elsevier, B.V.
Year of Publication: 2015
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 24 Surficial Geology, Quaternary Geology; Aliphatic hydrocarbons; Alkanes; Annamite Range; Asia; Australasia; Australia; Cenozoic; Chain length; Charcoal; China; Ecuador; Far East; Foraminifera; Glacial environment; Heqing Basin; Holocene; Hydrocarbons; Indicators; Interglacial environment; Invertebrata; Isotope ratios; Isotopes; La Nina; Laguna Pallcachoca; Leg 184; Lipids; Marine sediments; Microfossils; Middle Holocene; Miospores; N-alkanes; North Pacific; Northwest Pacific; O-18/O-16; ODP Site 1143; ODP Site 1144; Ocean Drilling Program; Organic compounds; Oxygen; Pacific Ocean; Paleoclimatology; Paleohydrology; Palynomorphs; Planktonic taxa; Pollen; Protista; Quaternary; Sediments; South America; South China Sea; South Pacific; Southern China; Southern Ecuador; Southwest Pacific; Stable isotopes; Tasman Sea; Tropical environment; Upper Quaternary; Vietnam; Waxes; West Pacific
Coordinates: N200311 N200311 E1172508 E1172508
N092143 N092143 E1131707 E1131707
N142230 N142230 E1104436 E1104436
Record ID: 2015071522
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands