@article {saravanan_reconstructing_2024,
	title = {Reconstructing hypoxia on the eastern Arabian sea continental shelf during the past \~{}7400 years: A multi-proxy approach},
	journal = {Quaternary International},
	year = {2024},
	abstract = {Shallow-sea environmental variations in the eastern Arabian Sea (EAS) have been related to monsoon variability, poorly ventilated intermediate water, and primary productivity changes. To understand these conditions, benthic foraminiferal assemblages, oxygen isotope ratios, and total organic carbon content have been examined in sediment Core SK291/GC13 from the EAS. We aim to retrieve decadal to centennial time-scale changes in past oxygenation and paleoproductivity during the last 7400 calibrated years before the present (cal yr BP). Our proxy data suggest that the oxic benthic foraminifera species were dominant during \~{}7400{\textendash}6000~cal~yr BP. The change from oxic to dysoxic occurred during ca. 6000{\textendash}3500~cal~yr BP, and transition from dysoxic to suboxic environmental conditions happened at ca. \~{}3500~cal~yr BP. These changes are contemporaneous with weakening of the Indian summer monsoon beginning at \~{}5500~cal~yr BP which culminated into a major arid phase so-called ca 4.2 ka event in the Indian subcontinent. The EAS experienced low productivity during the early phase of our studied interval (\~{}7400{\textendash}6000~cal~yr BP) and higher productivity in the middle Holocene (6000{\textendash}3000~cal~yr BP), as revealed by the total organic carbon and benthic assemblages. Furthermore, productivity increased in the warm period and decreased in the Little Ice Age on a decadal scale. The spectral analysis of total organic content and suboxic species indicates a 23-year Hale (solar) cycle during the last millennium, indicating a close relationship between solar activity and monsoon variability. The strengthening of the El Nino-Southern Oscillation perhaps amplified due to increased solar activity in the last millennium, which influenced the climate of the EAS. The study highlights paleo-oxygenation shifts based on benthic foraminiferal assemblages, which are crucial for understanding changes in the oxygen minimum zones (OMZs) and their potential impacts on marine ecosystems.},
	keywords = {Benthic assemblages, Goa coast, Hale cycle, Little ice age, Oxygen minimum zone, Suboxic environment},
	issn = {1040-6182},
	doi = {10.1016/j.quaint.2024.05.007},
	url = {https://www.sciencedirect.com/science/article/pii/S1040618224001630},
	author = {Saravanan, Ponnusamy and Gupta, Anil K. and Li, Xiangzhong and Zheng, Hongbo and Panigrahi, Mruganka K.}
}
@article {2893,
	title = {Response of shallow-sea benthic foraminifera to environmental changes off the coast of Goa, eastern Arabian Sea, during the last \~{}6100 cal yr BPAbstract},
	journal = {Geological Magazine},
	volume = {157},
	year = {2020},
	month = {Jan-03-2020},
	pages = {497 - 505},
	abstract = {We have analysed a 6100-year record of benthic and planktonic foraminifera from inner neritic sediments from Core SK291/GC13, off the Goa coast, eastern Arabian Sea, to understand the response of benthic foraminifera to shallow-marine processes. The benthic foraminiferal assemblage is dominated by Nonion cf. asterizans, Ammonia beccarii, A. gaimardii and Virgulinella fragilis, which have been selected on the basis of a population of 10\% or more in any three samples analysed. The planktonic foraminiferal population is sporadic and rare, with Globigerinoides ruber as the predominant species showing a variable trend. The foraminiferal proxies combined with total organic carbon (wt\%) and δ13C and δ18O values of Ammonia gaimardii suggest distinct variations, indicating changes in productivity and salinity in the shallow eastern Arabian Sea. The coastal waters off Goa were relatively warmer and less saline between 6100 and 4600, or perhaps to 4200, calibrated years before the present (cal yr BP), corresponding to a stronger monsoon in South and East Asia. The shallow sea was cooler from ~4200 to 2600 cal yr BP in the study area, coinciding with a lower sea surface temperature in the northeastern Arabian Sea and an arid phase in the Indian subcontinent. From 2900 to 2600 cal yr BP the study core exhibits the impacts of short-term cold events, which have earlier been observed in the northeastern Arabian Sea, off Pakistan. During the Little Ice Age, the shallow sea off Goa was less productive.},
	keywords = {arabian sea, benthic foraminifera, Indian monsoon, Stable isotopes, western continental margin of India},
	issn = {0016-7568},
	doi = {10.1017/S0016756819000979},
	url = {https://www.cambridge.org/core/product/identifier/S0016756819000979/type/journal_article},
	author = {Saravanan, Ponnusamy and Gupta, Anil K. and Zheng, Hongbo and Panigrahi, Mruganka K. and Tiwari, Sameer K. and Rai, Santosh K. and Prakasam, Muthusamy}
}
@article {2892,
	title = {Late Holocene long arid phase in the Indian subcontinent as seen in shallow sediments of the eastern Arabian Sea},
	journal = {Journal of Asian Earth Sciences},
	volume = {181},
	year = {2019},
	month = {Jan-09-2019},
	pages = {103915},
	abstract = {Multi-proxy record of benthic and planktic foraminifera, total organic carbon and carbon and oxygen isotope ratios from Core SK291/GC15, off the coast of Goa, eastern Arabian Sea reveals significant paleoceanographic and paleoclimatic turnovers during ~6000 to 1700 calibrated years before the Present (cal yr BP). Benthic foraminiferal census data was analyzed with multivariate techniques including factor and cluster analyses of highest ranked species from the studied core that enabled to identify seven biofacies. The record suggests centennial to millennial-scale changes in the surface conditions driven by monsoon-linked upwelling in the eastern Arabian Sea during the studied interval. Various benthic biofacies combined with isotope and planktic foraminiferal data suggest that depletion of dissolved oxygen and increase in organic productivity in the study area was caused by intense monsoonal upwelling since the middle Holocene. The results suggest that during 5400{\textendash}4700 and 3000{\textendash}2500 cal yr BP the southwest (SW) monsoon was strong leading to intense upwelling in the study area as reflected by increased Globigerina bulloides percentages. These were generally warmer intervals in the northern hemisphere. The SW monsoon significantly weakened (abrupt decrease in G. bulloides population) during 4700{\textendash}3400 cal yr BP roughly coinciding with a long arid phase in the Indian subcontinent and a cold interval in Europe. Our record suggests an abrupt increase in SW monsoon intensity during ~3000 to 2500 cal yr BP, when a pronounced change in benthic biofacies is also noted that suggests a major shift in the sub-surface conditions. Our data document a prolong weak SW monsoon phase beginning at ~4600 cal yr BP, little earlier than 4.2 ka event, in the eastern Arabian Sea.},
	issn = {13679120},
	doi = {10.1016/j.jseaes.2019.103915},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S1367912019302676},
	author = {Saravanan, Ponnusamy and Gupta, Anil K. and Zheng, Hongbo and Panigrahi, Mruganka K. and Prakasam, Muthusamy}
}
