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Modern and past processes of ocean-atmosphere-climate interactions in the low-latitude western Pacific and Indian Ocean
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Climate Variability during the Holocene as seen in Sediments from the Southeastern Arabian Sea Wednesday 9th @ 1130-1150, Conference Room 1 Yoganandan Veeran* , Assistant Professor SivaChandiran Alagudurai, Research Scholar Selvaraj Kandasamy, Professor Presenter Email: yoganandan1@gmail.com |
The Indian summer monsoon (ISM) system is a key component of the global climate, and has a significant role in the socioeconomic life of the people of the Indian subcontinent and also in some parts of SW China. Here our goal is to reconstruct the Holocene history of the ISM and for that we used a high resolution marine sediment core SK-313/GC-1 retrieved from off Cochin in the southeastern Arabian Sea. We examined 291 subsamples for abundances of benthic and planktonic foraminifera to understand paleomonsoon-related surface productivity changes in the study area during the Holocene. The chronology of the core is based on five Accelerator Mass Spectrometry radiocarbon (AMS 14C) dates on mixed planktonic foraminifera. Seasonal changes in the oceanography are reflected in benthic and planktonic foraminiferal productivity. We identified benthic and planktonic foraminifera, characteristic of specific environments, to understand the Holocene monsoonal variability. We focused on oceanographically important benthic and planktonic foraminifera species such as Buliminamarginata, Bolivinaspathulata,Globigerina bulloides, Globigerinoidesruber ,Neogloqudrinadutertrei, Uvigerinaperigrina, Uvigerinaproboscidea, etc. Higher population of mixed layer species Globigerinoides ruber coincides with low contents of species of upwelling indicator, Globigerina bulloides. The population flux of planktonic foraminifera Globigerina bulloides and Neogloqudrina dutertrei suggests that phases of weak summer monsoons prevailed during the early to middle Holocene, whereas a strong summer monsoon during the late Holocene; the pattern is opposite to the monsoon pattern inferred from G. bulloides abundances in the western Arabian Sea.
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