- Dona Paula, Goa, India.
- +91-0832- 2450327
- iiosc2020[at]nio[dot]org
Abstract Submission No. | ABS-2022-10-0264 |
Title of Abstract | Spatio-temporal variation of sedimentation rate in the south-eastern Arabian Sea over the last ~50 ka |
Authors | M. Muruganantham*, Bisweswar Sahoo, Arvind Shukla, Pankaj Kumar, Sunil Kumar Singh |
Organisation | CSIR-National Institute of Oceanography, Goa |
Address | Integrative Oceanography Division, Dona Paula, Goa-403004 Panaji, Goa, India Pincode: 403004 Mobile: 6351565623 E-mail: vmmuruga@gmail.com |
Country | India |
Presentation | Oral |
Abstract | Marine sediments serve as an important archive to extract the paleoclimatic and palaeoceanographic information. The sedimentation rates in the marine system are highly variable across time and space and depend on proximity to riverine influx, aeolian input, ocean bathymetry and water depth, ocean currents, biological productivity, climatic variation, sea-level fluctuations, wind direction and strength and tectonic activities. During the 60th voyage of ORV Sindhu Sadhana in the year 2019, two sediment cores SSD060-GC02 (10° N and 74.2° E) off Kochi and SSD060-GC10 (14 N and 72.2 E) off Karnataka in the South-Eastern Arabian Sea (SEAS) were raised in water depths of 2475 m and 2055 m, respectively with major objective to better understand the climatic variability and it impact on erosion, and sediment deposition during the last several thousand years. The chronology of the retrieved sediment cores was obtained by dating mixed planktonic foraminifera by measuring 14C using AMS at IUAC Delhi. The core GC02 and GC10 were dated to have a depositional history up to 48 ka and 36 ka, respectively. The core GC02 collected off Kochi has an average sedimentation rate of 24.0 cm/kyr, while GC10 was deposited at 16.5 cm/kyr. The sedimentation rates in the core GC 02 varied moderately during the pre-glacial period (33.6 cm/kyr), highest during the glacial period (46.8 cm/kyr), fell during the glacial-interglacial transition period (11 cm/kyr), and was lowest during the Holocene (4.6 cm/kyr). In GC-10, off Karnataka, sedimentation rates were 24.8 cm/kyr during the pre-glacial period, 12 cm/kyr during the LGM, maximum (48.0 cm/kyr) at the glacial-interglacial transition, and declining (19 cm/kyr) during the Holocene. Observed temporal and spatial variabilities in the sedimentation rates in SEAS can be explained by the interplay among variabilities in the intensities of SW vs NE monsoon and decrease in sea-level during LGM causing decrease in erosion rates in the source regions, sluggish transport of sediments and bypassing the continental shelf region. In addition, temporal variation in the biological productivity could be partly responsible for fluctuating sedimentation rates in this region. |