Measurement of submarine groundwater discharge (SGD) into Tiruchendur coast at southeast India using 222Rn as a naturally occurring tracer.

Application of natural tracers such as radon isotope mass balance has been useful in estimating the submarine groundwater discharge (SGD). This study used ²²²Rn and evaluated the magnitude of SGD at Tiruchendur coast of southeast India in the Gulf of Mannar (Indian Ocean). Higher magnitudes of ²²²Rn in the porewater and seawater in comparison with the groundwater suggest simultaneous SGD with fluxes of 0.1–0.25 m³ m⁻² d⁻¹ at offshore and 0.4–0.20 m³ m⁻² d⁻¹ at the near shore. These baseline data would contribute to the management and protection of the Gulf of Mannar region in near future. [Display omitted] • Quantification of groundwater discharge (SGD) at southeast coast of India using ²²²Rn mass balance. • SGD fluxes of 0.1–0.25 m³ m⁻² d⁻¹ at offshore and 0.4–0.20 m³ m⁻² d⁻¹ at nearshore. • Simultaneous SGD through comparison of magnitudes of ²²²Rn in porewater and seawater with the groundwater. • Necessity of public awareness for better coastal management and environmental protection at Gulf of Mannar (Indian Ocean). [ABSTRACT FROM AUTHOR]