01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-06-0126 |
| Title of Abstract | Present and past carbon accumulation in the northeast Indian Ocean |
| Authors | Rajeev Saraswat* |
| Organisation | CSIR-National Institute of Oceanography |
| Address | CSIR-National Institute of Oceanography Dona Paula, Goa, India Pincode: 403004 E-mail: rsaraswat.nio@csir.res.in |
| Country | India |
| Presentation | Oral |
| Abstract | The excessive release of carbon dioxide (CO2) into the atmosphere as a result of anthropogenic activities, is a major concern. The oceans help remove a significant amount of atmospheric CO2 through organic (Corg) and inorganic carbon (CaCO3) sequestration. The ocean's ability to bury carbon varies depending on several factors. We studied the factors affecting the basin scale spatio-temporal variation in carbon burial in the climatically sensitive northeast Indian Ocean, by using the data [CaCO3, Corg, Corg/Nitrogen, and isotopic ratio (δ13C, δ15N) of organic carbon] from a total of 718 surface sediments and 19 cores. The entire continental shelf and slope contain <10% CaCO3. The highest CaCO3 is in the deepest parts of the central northeast Indian Ocean, away from the mouth of major river systems. Despite of the high productivity, the low Corg on the continental shelf is attributed to the well-oxygenated coarse-grained sediments. The lowest Corg is found in the well-oxygenated deeper central northeast Indian Ocean. Interestingly, the highest total carbon is in the deeper central and equatorial regions, far away from the highly productive marginal marine regions. We also report that different regions of the ocean stored varying amounts of carbon, indicating a strong spatial heterogeneity in carbon burial since the last deglaciation. During the last glacial maximum (LGM), the sediments' CaCO3 content decreased in the deep sea but increased on the shelf. The opposite was true for Corg burial patterns, with values higher than recent throughout the LGM, and the highest Corg content during LGM. Marginal seas' carbon burial changes were mainly influenced by monsoon-induced productivity, sedimentation rate, sediment texture, and dissolved oxygen concentration. On the other hand, water mass changes primarily drove carbon burial in deeper regions. The findings will help in assessing the carbon burial potential of this region in the warming world. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Carbon, calcium carbonate, Indian Ocean, sediments |
| For Awards | no |