First evidence of denitrification vis-à-vis monsoon in the Arabian Sea since Late Miocene

Tripathi, Shubham; Tiwari, Manish; Lee, Jongmin; Khim, Boo‐Keun; Pandey, Dhananjai K.; Clift, Peter D.; Kulhanek, Denise K.; Andó, Sergio; Bendle, James; Aharonovich, Sophia; Griffith, Elizabeth M.; Gurumurthy, G P; Hahn, Annette; Iwai, Masao; Kumar, Anil; Kumar, A. Ganesh; Liddy, Hannah M.; Lu, Huayu; Lyle, Mitchell W; Mishra, Ravi; Radhakrishna, T.; Routledge, Claire M.; Saraswat, Rajeev; Saxena, R. K.; Scardia, Giancarlo; Sharma, Girish Kumar; Singh, Arun D.; Steinke, Stephan; Suzuki, Kenta; Tauxe, Lisa; Xu, Zuyan; Yu, Zhaojie

doi:10.1038/srep43056

Cited by 47 publications

(61 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The increase in δ 15 N (Figure d) in conjunction with increased abundance of diatoms, TOC, and the Ba/Al ratio suggests that denitrification is occurring in the water body in response to increased organic matter load (Narkis et al, ). Based on previous studies in the region (Altabet et al, ; Altabet et al, ; Gaye‐Haake et al, ; Tripathi et al, ) δ 15 N values above 6‰ have been ascribed to indicate sustained denitrification in the water column. In the Miocene record of Site 722, δ 15 N increases above 6‰ for the first time ~11 Ma.…”

Section: Discussionmentioning

confidence: 98%

“…This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. denitrification in the region and concluded that productivity did not significantly increase prior to 3.1 Ma during the Mid-Pliocene Warm Period (Tripathi et al, 2017). Tripathi et al (2017) thus assume that a weaker SAM must have persisted from at least~10.2 Ma onward.…”

Section: The Indian Ocean Oxygen Minimum Zonementioning

confidence: 95%

“…Their study also reports a major cooling step between 11 and 10 Ma, interpreted as the initiation of the upwelling and increased productivity along the Oman Margin. However, studies utilizing nitrogen isotopes from the eastern Arabian Sea indicate no denitrification in the region and concluded that productivity did not significantly increase prior to 3.1 Ma during the Mid‐Pliocene Warm Period (Tripathi et al, ). Tripathi et al () thus assume that a weaker SAM must have persisted from at least ~10.2 Ma onward.…”

Section: Introductionmentioning

confidence: 99%

“…However, studies utilizing nitrogen isotopes from the eastern Arabian Sea indicate no denitrification in the region and concluded that productivity did not significantly increase prior to 3.1 Ma during the Mid‐Pliocene Warm Period (Tripathi et al, ). Tripathi et al () thus assume that a weaker SAM must have persisted from at least ~10.2 Ma onward. Their assumption is in contradiction with Dickens and Owen (, 1994), who, using multiple lines of evidence, illustrate the presence of increased productivity in the Indian Ocean at least from 9 Ma and up to 5 Ma.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Monsoons, Upwelling, and the Deoxygenation of the Northwestern Indian Ocean in Response to Middle to Late Miocene Global Climatic Shifts

Bialik

Auer

Ogawa

et al. 2020

Paleoceanog and Paleoclimatol

View full text Add to dashboard Cite

Today, upwelling along the Oman margin in the Arabian Sea is governed by the South Asian Monsoon winds. The Oman upwelling results in the formation of an oxygen minimum zone (OMZ) spanning across the Arabian Sea and large parts of the Indian Ocean. While these conditions are recorded as early as the middle Miocene (~15 Ma), the long‐term dynamics of upwelling in the Arabian Sea are as of yet poorly constrained during the middle to late Miocene. Here, we use organic and inorganic proxies combined with sedimentary and paleontological records to constrain the evolution of upwelling at Ocean Drilling Program Site 722B between ~15 and ~8.7 Ma. Our record shows that Mn depletion occurred at ~14.5 Ma, likely due to regionally confined OMZ formation at that time. Biogenic silica accumulation intensified between ~12.5 and ~11 Ma. The δ15N values (>6‰) provide evidence for the onset of at least intermittent denitrification between ~11 and ~9.5 Ma during the apex of the global “carbonate crash.” Our data demonstrate that upwelling and OMZ intensity in the Arabian Sea were linked to the reorganization of the Indian Ocean circulation system and South Asian Monsoon during the Miocene. The initiation of these systems occurred once the regional tectonic configuration (i.e., the uplift of the Tibetan Plateau ~25 Ma and the closure of the Tethyan seaway ~20 Ma) was in place. The subsequent development of monsoonal upwelling after 14 Ma responded to latitudinal shifts in climatic belts following the progressive Miocene glaciation of Antarctica.

show abstract

Section: Discussionmentioning

confidence: 98%

Section: The Indian Ocean Oxygen Minimum Zonementioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Monsoons, Upwelling, and the Deoxygenation of the Northwestern Indian Ocean in Response to Middle to Late Miocene Global Climatic Shifts

Bialik

Auer

Ogawa

et al. 2020

Paleoceanog and Paleoclimatol

View full text Add to dashboard Cite

show abstract

“…Despite the significance of denitrification in global climate change, no long-term record of its evolution in the Arabian Sea during the Miocene-Pliocene period existed till date; the longest record available goes back to 1 million years from the western Arabian Sea (Altabet et al, 1999). To fill this gap, Tripathi et al (2017) studied various denitrification (δ 15 N of sedimentary organic matter, SOM), provenance (δ 13 C of SOM, C/N ratio) and productivity (total organic carbon (TOC) and total nitrogen (TN)) proxies in sediment record of the IODP Site U1456, spanning the last 10 Myr (Fig. 3).…”

Section: Records Of Past Changes In Ocean-climate During the Neogenementioning

confidence: 99%

Recent advances in understanding Neogene climatic evolution: Indian perspective

Singh¹,

Ghosh²,

Mehrotra³

et al. 2020

PINSA

View full text Add to dashboard Cite

This article presents an overview of the research work done during 2015-2019 on the South Asian/Indian monsoon climate variability, based on the Neogene terrestrial and marine proxy records. The paleoclimatic and paleoceanographic records provide better insights into our current understanding of timing of initiation/intensification of the Indian monsoon system; its evolution and seasonal variability pattern through time and underlying mechanisms; and impacts on paleobiogeography of terrestrial fauna and flora and physico-chemical and biological processes in the northern Indian Ocean. The Neogene upliftment history of the Himalaya was reconstructed based on detailed analysis of fossil flora from Himalayan sequences and a link between step wise uplift of Himalaya-Tibetan plateau and Indian summer monsoon intensification was established. The rainfall pattern in the northeast India during the Neogene period was quantified; and the new data suggest the presence of rainfall in the region since 11.6 Ma. δ 13 C record of pedogenic nodules in Siwalik succession provides evidence of major shift in vegetation between ~2.8 Ma and 1.1 Ma due to large variation in temperature and precipitation. New results of the multiproxy based paleoceanographic studies carried out on sediment cores collected during recent IODP expeditions in the Arabian Sea and Bay of Bengal, have major implications on the evolution of the Indian monsoon and dynamics of its seasonal variations in the Neogene. The sedimentological and geochemical records from carbonate platform of the Maldives suggest an abrupt onset of modern monsoon circulation at ~ 12.9 Ma, which cannot be entirely explained by the Himalayan tectonics as many believed earlier. It appears that the global climate also controls Indian monsoon circulation, in addition to the tectonics. Record of past changes in the Arabian Sea denitrification driven mainly by monsoon-wind induced productivity and water column ventilation condition, reveals that the Indian monsoon intensified during ~2.8-3.2 Ma. Recently, based on the integrated multiple proxy records it was inferred that seasonal monsoon circulation was weak during 1.85-2.7 Ma, subsequently followed by the intensification of winter monsoon between ~1.65 and 1.85 Ma, attributed to the development of strong zonal and meridional circulations due to enhanced E-W Pacific temperature gradients.

show abstract

Biogeochemistry of Nitrogen in the Marine System with Special Emphasis on the Arabian Sea and Bay of Bengal

Sivan

Mazumdar

Peketi

et al. 2022

Systems Biogeochemistry of Major Marine Biomes

View full text Add to dashboard Cite

First evidence of denitrification vis-à-vis monsoon in the Arabian Sea since Late Miocene

Cited by 47 publications

References 39 publications

Monsoons, Upwelling, and the Deoxygenation of the Northwestern Indian Ocean in Response to Middle to Late Miocene Global Climatic Shifts

Monsoons, Upwelling, and the Deoxygenation of the Northwestern Indian Ocean in Response to Middle to Late Miocene Global Climatic Shifts

Recent advances in understanding Neogene climatic evolution: Indian perspective

Biogeochemistry of Nitrogen in the Marine System with Special Emphasis on the Arabian Sea and Bay of Bengal

Contact Info

Product

Resources

About