Year: 2017
Type: article
Abstract: In the Arabian Sea, South Asian monsoon (SAM)-induced high surface water productivity coupled with poor ventilation of intermediate water results in strong denitrification within the oxygen minimum zone (OMZ). Despite the significance of denitrification in the Arabian Sea, we have no long-term record of its evolution spanning the past several million years. Here, we present the first record of denitrification evolution since Late Miocene (~10.2 Ma) in the Eastern Arabian Sea, where the SAM generates moderate surface water productivity, based on the samples retrieved during the International Ocean Discovery Program (IODP) Expedition 355. We find that (i) the SAM was persistently weaker from ~10.2 to 3.1 Ma; it did not intensify at ~8 Ma in contrast to a few previous studies, (ii) on tectonic timescale, both the SAM and the East Asian Monsoon (EAM) varied synchronously, (iii) the first evidence of denitrification and productivity/SAM intensification was at ~3.2-2.8 Ma that coincided with Mid-Pliocene Warm Period (MPWP), and (iv) the modern strength of the OMZ where denitrification is a permanent feature was attained at ~1.0 Ma.
Source: Scientific Reports
DOI: 10.1038/srep43056
Authors: Shubham Tripathi, Manish Tiwari, Jongmin Lee, Boo-Keun Khim, IODP Expedition 355 Scientists, Dhananjai K. Pandey, Peter D. Clift, Denise K. Kulhanek, Sergio Andò, James A.P. Bendle, Sophia Aharonovich, Elizabeth M. Griffith, Gundiga P. Gurumurthy, Annette Hahn, Masao Iwai, Anil Kumar, A. Ganesh Kumar, Hannah M. Liddy, Huayu Lu, Mitchell W. Lyle, Ravi Mishra, Tallavajhala Radhakrishna, Claire M. Routledge, Rajeev Saraswat, Rakesh Saxena, Giancarlo Scardia, Girish K. Sharma, Arun D. Singh, Stephan Steinke, Kenta Suzuki, Lisa Tauxe, Zhaokai Xu, Zhaojie Yu
Institutions: National Centre for Polar and Ocean Research, Pusan National University, Louisiana State University, Texas A&M University, University of Milano-Bicocca, University of Birmingham, Macquarie University, The University of Texas at Arlington, Manipal Academy of Higher Education, Manipal Centre for Natural Sciences, University of Bremen, University of Kochi, Marine Core Research Institute, Kochi University, Kōchi University, Wadia Institute of Himalayan Geology, National Institute of Ocean Technology, University of Southern California, Nanjing University, Oregon State University, National Centre for Earth Science Studies, University College London, National Institute of Oceanography, Oil and Natural Gas Corporation (India), Universidade Estadual Paulista (Unesp), Kumaun University, Banaras Hindu University, Xiamen University, Hokkaido University, Scripps Institution of Oceanography, Chinese Academy of Sciences, Institute of Oceanology, Université Paris-Sud, Centre National de la Recherche Scientifique, Geosciences Paris-Saclay
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,690
OpenAlex ID: W2591368705