Variation of terrestrial input and paleoproductivity in the Arabian Sea; millennial-scale variations of the Indian monsoon during the Quaternary as recorded at IODP Exp. 355

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Author(s): Hahn, Annette; Ando, Sergio; Bowen, Melanie; Clift, Peter; Gorgas, Thomas; Kulhanek, Denise; Lyle, Mitchelle; Saraswat, Rajeev
Author Affiliation(s): Primary:
University of Bremen, Bremen, Germany
University of Milano-Bicocca, Italy
Louisiana State University, United States
Deutsche GeoForschungsZentrum, Germany
Texas A&M University, United States
Oregon State University, United States
National Center of Oceanography, India
Volume Title: European Geosciences Union general assembly 2018
Source: Geophysical Research Abstracts, Vol.20; European Geosciences Union general assembly 2018, Vienna, Austria, April 8-13, 2018. Publisher: Copernicus GmbH on behalf of the European Geosciences Union (EGU), Katlenburg-Lindau, Germany. ISSN: 1029-7006
Note: In English
Summary: The Indian monsoon is a major component of the global climate system. Variation in the yearly moist and dry episodes affect livelihood of the densely populated northwest Indian region. In order to develop mitigation strategies at a regional scale, it is necessary to accurately predict local future climatic trends. Unfortunately, there is a scarcity of long continuous, high-resolution climate archives recording the variability of both atmospheric and oceanic processes. The sediment cores obtained from the Indus fan during IODP Exp. 355 (Arabian Sea monsoon) have the potential to fill this gap. We use time and cost saving methods (FTIRS and XRF) in order to obtain high resolution records spanning the past 1.5 Ma to simultaneously reconstruct terrestrial paleoclimatic conditions (using element ratios and mineralogical data as weathering and provenance indicators) and paleooceanographic circulation patterns (using paleoproductivity proxies) at millennial scale resolution. Preliminary findings indicate that a higher supply of eroded material from the Karakorum is associated with stronger westerlies and a decreased monsoon during glacials, whereas interglacials are characterized by a dominant supply of Himalayan eroded material due to strong monsoon rainfalls and weak Westerlies. Furthermore, the preliminary paleoproduction record indicates that increased productivity in the eastern Arabian Sea resulted from stronger winter monsoon winds during glacials. Our preliminary data suggest that an anti-phase relationship of the Westerlies and the Arabian Sea Monsoon exists for both orbital scale (glacial-interglacial) and millennial scale variability during the past 1.2Ma. Preliminary spectral analysis shows a shift from a precession to a obliquity driving at around 0.35Ma, furthermore there are indications of a co-presence of the major Milankovich cycles during intervals of high sedimentation rate such as 0.12Ma. The mechanisms behind this are yet to be explored and completing this dataset at higher resolution will lead to a more comprehensive understanding of the interplay of the local atmospheric and oceanic circulation processes over glacial-interglacial cycles; an essential prerequisite for regional predictions of global climate change impacts. [Copyright Author(s) 2018. CC Attribution 4.0 License:]
Year of Publication: 2018
Research Program: IODP2 International Ocean Discovery Program
Key Words: 24 Surficial Geology, Quaternary Geology; Arabian Sea; Cenozoic; Climate change; Cores; Expedition 355; Global change; Indian Ocean; International Ocean Discovery Program; Marine sediments; Monsoons; Paleoclimatology; Paleoecology; Productivity; Quaternary; Sediments
Coordinates: N163715 N171000 E0685100 E0675500
Record ID: 2019066719
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from European Geosciences Union, Munich, Germany