Submarine groundwater discharge derived strontium from the Bengal Basin traced in Bay of Bengal water samples

Chakrabarti, Ramananda and Mondal, Surajit and Acharya, Shiba Shankar and Lekha, J Sree and Sengupta, Debasis (2018) Submarine groundwater discharge derived strontium from the Bengal Basin traced in Bay of Bengal water samples. In: SCIENTIFIC REPORTS, 8 .

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Abstract

Evaluating the submarine groundwater discharge (SGD) derived strontium (Sr) flux from the Bengal Basin to the Bay of Bengal (BoB) and determining its isotopic composition is crucial for understanding the marine Sr isotopic evolution over time. Measurements of spatially and temporally distributed water samples collected from the BoB show radiogenic Sr-87/Sr-86, high Sr, calcium (Ca) concentrations and high salinity in samples collected dominantly from 100-120 m depth, which can be explained only by the contribution of saline groundwater from the Bengal Basin. These results provide a direct evidence of the SGD-Sr flux to the BoB. This SGD-Sr flux is however, spatially heterogeneous and using conservative hydrological estimates of the SGD flux to the BoB, we suggest a SGD Sr flux of 13.5-40.5 x 10(5) mol/yr to the BoB. Mass balance calculations using Sr concentrations and Sr-87/Sr-86 suggest up to 7% contribution of SGD to the 100-120 m BoB water samples. The identification of SGD at 100-120 m depth also provides an explanation for the anomalous variations in barium (Ba) concentrations and the delta O-18-salinity relationship in intermediate depths of the BoB.

Item Type:	Journal Article
Publication:	SCIENTIFIC REPORTS
Publisher:	NATURE PUBLISHING GROUP, MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
Additional Information:	Copy right for the article belong to NATURE PUBLISHING GROUP, MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
Department/Centre:	Division of Mechanical Sciences > Centre for Earth Sciences Division of Interdisciplinary Sciences > Interdisciplinary Centre for Water Research Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited:	02 Apr 2018 19:58
Last Modified:	12 Oct 2018 14:07
URI:	http://eprints.iisc.ac.in/id/eprint/59439

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