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| Abstract Submission No. | ABS-2022-10-0019 |
| Title of Abstract | Contrasting trend in inorganic and organic carbon burial in the west-central Bay of Bengal, during the last glacial-interglacial interval |
| Authors | Suokhrie, T.,*, Saraswat, R., |
| Organisation | CSIR- National Institute of Oceanography, Goa |
| Address | CSIR-NATIONAL INSTITUTE OF OCEANOGRAPHY PANAJI, GOA, India Pincode: 403004 Mobile: 8805160762 E-mail: tsuokhrie@nio.org |
| Country | India |
| Presentation | Oral |
| Abstract | The oceans are vital in global carbon cycling as they act as both carbon source and sink. Therefore, changes in sedimentary inorganic and Corg can provide clues about carbon cycling during glacial-interglacial timescales. Here, we reconstructed multidecadal inorganic and Corg burial record for the last ~28kyr, from a 4m gravity core collected off Pennar river in the west-central Bay of Bengal. The relative abundance of selected planktic foraminifera and stable isotopic ratio (δ18O) were used to understand the factors affecting the carbon burial in this region. Total carbon content of the glacial (~11-24kyr) sediments was double of the Holocene sediments due to increased CaCO3 content which is in contrast with the relatively lower Corg and decreased abundance of G. bulloides and N. dutertrei. The Corg/TN value indicative of marine organic matter coupled with relative decreased abundance of G. bulloides suggests reduced precipitation contributing less terrigenous flux. implying better preservation and reduced dilution to cause the increased glacial CaCO3. Contrastingly, lower CaCO3 abundance during Holocene coincides with increased upwelling indicator species and an overall Corg increase suggesting a relatively higher productivity and intense precipitation leading to increased dilution during δ18O also suggests increased precipitation during Holocene. Furthermore, we document signatures of Northern Hemisphere cold events particularly, Heinrich 1, 2 suggesting the influence of northern latitudinal events on the tropical Indian Ocean. The datasets reveal interesting aspects on carbonate preservation and productivity during glacial-interglacial timescales furthering our knowledge on carbon storage/inventory in the northern Indian Ocean. |