Productivity controls on the redox variation in the southeastern Arabian Sea sediments during the past 18 kyr

Pattan, J.N.; Parthiban, G.; Amonkar, Ankeeta

doi:10.1016/j.quaint.2019.05.034

Cited by 4 publications

(7 citation statements)

References 57 publications

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“…Thus, the preservation of foraminiferal carbonate in the ocean sediments resulting in long-term carbon burial, varies regionally (Naik et al 2017) and depends on sedimentation rate (Agnihotri et al 2003 b ) and bottom water conditions (pH, CaCO 3 compensation depth). Earlier, similar higher productivity and extreme suboxic condition during the late Holocene (5.5 ka to present) were reported from the SE Arabian Sea (Pattan et al 2019). Therefore, the consistent increase in CaCO 3 in the Gulf of Mannar suggests persistence of conditions favouring carbon burial in the sediments.…”

Section: Discussionsupporting

confidence: 87%

“…A similar consistent increase in CaCO 3 in the SE Arabian Sea, during the late Holocene, was also attributed to the strengthened monsoon (Sarkar et al 2000). The increasing trend in CaCO 3 in the Gulf of Mannar matches with another core (AAS-VI/GC-05) collected off Cochin from the SE Arabian Sea (Pattan et al 2019), suggesting a strong regional feature (Fig. 7).…”

Section: Discussionsupporting

confidence: 81%

“…7). The Gulf of Mannar CaCO 3 record is different than other SE Arabian Sea records (Nagoji & Tiwari, 2017, Naik et al 2017), but strikingly similar to another core, AAS-VI/GC-05, collected from a depth of 280 m in the SE Arabian Sea (Pattan et al 2019). The SE Arabian Sea is influenced by upwelling-induced primary productivity during the summer season.…”

Section: Discussionmentioning

confidence: 45%

“…The calcareous skeletons also sequester a substantial fraction of carbon and bury it in the ocean sediments. Thus the CaCO 3 in the sediments is influenced by productivity, dissolution of CaCO 3 and dilution by terrigenous material (Naidu, 1991; Pattan et al 2019). The shift in monsoon-induced evaporation–precipitation during the Holocene was synchronous with a change in surface productivity, planktic foraminiferal abundance and coarse sediment fraction (Saraswat et al 2016).…”

Section: Discussionmentioning

confidence: 99%

“…

Fig. 1. The core location and other cores from the eastern Arabian Sea (SO90-39 KG/SO130-275 KL, Böll et al 2014; SO90-63 KA, Burdanowitz et al 2019; SK240/485, Azharuddin et al 2017; SK291 GC15, Saravanan et al 2019; SN-6, Nagoji & Tiwari, 2017; AAS-VI/GC-05, Pattan et al 2019; SK237 GC04, Naik et al 2017) discussed in the paper. The filled black square is the location of core SSD004 GC02 in the Gulf of Mannar.…”

Section: Study Areamentioning

confidence: 99%

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Persistent increase in carbon burial in the Gulf of Mannar, during the Meghalayan Age: Influence of primary productivity and better preservation

et al. 2023

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The oceans store a substantial fraction of carbon as calcium carbonate (CaCO3) and organic carbon (Corg) and constitute a significant component of the global carbon cycle. The Corg and CaCO3 flux depends on productivity and is strongly modulated by the Asian monsoon in the tropics. Anthropogenic activities are likely to influence the monsoon and thus it is imperative to understand its implications on carbon burial in the oceans. We have reconstructed multi-decadal CaCO3 and Corg burial changes and associated processes during the last 4.9 ky, including the Meghalayan Age, from the Gulf of Mannar. The influence of monsoon on carbon burial is reconstructed from the absolute abundance of planktic foraminifera and relative abundance of Globigerina bulloides. Both Corg and CaCO3 increased throughout the Meghalayan Age, except between 3.0–3.5 ka and the last millennium. The increase in Corg burial during the Meghalayan Age was observed throughout the eastern Arabian Sea. The concomitant decrease in the Corg to nitrogen ratio suggests increased contribution of marine organic matter. Although the upwelling was intense until 1.5 ka, the lack of a definite increasing trend suggests that the persistent increase in Corg and CaCO3 during the early Meghalayan Age was mainly driven by higher productivity during the winter season coupled with better preservation in the sediments. Both the intervals (3.0–3.5 ka and the last millennium) of nearly constant carbon burial coincide with a steady sea-level. The low carbon burial during the last millennium is attributed to the weaker-upwelling-induced lower productivity.

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Section: Discussionsupporting

confidence: 87%

Section: Discussionsupporting

confidence: 81%