Vol.:(0123456789) 1 3 Journal of Radioanalytical and Nuclear Chemistry https://doi.org/10.1007/s10967-021-07740-w A comprehensive study on sedimentation rate and sediment age of Satopanth Tal Garhwal Himalaya, using 210 Pb and  137 Cs techniques Subhrajit Das 1  · Sivaprakasam Vasudevan 1 Received: 25 January 2021 / Accepted: 16 April 2021 © Akadémiai Kiadó, Budapest, Hungary 2021 Abstract Radionuclides dating have been applied in the chronological series of sediment core recovered from Satopanth Tal to esti- mate the sedimentation rate and its age. Several models include CRS and slope method, and 137 Cs peak methods have been adopted. The depth concentration of 210 Pb exc in the core determines the various parameters like sedimentation rate, geochro- nology, inventory, and mass fuxes. The CRS model and slope method infer the sediments deposited at a rate of 0.79 ± 0.04 cm/year dated to 120 years. Distinct peaks on 1963 and 1986AD, the 137 Cs record estimate the mean sedimentation rate is 0.745 ± 0.03 cm/year respectively and dated to 77 years. Keywords Radionuclide · Caesium-137 ( 137 Cs) · Lead-210 ( 210 Pb) · Inventory · Mass fux · Constant rate of supply (CRS) Introduction Mountains provide homes for about 12% of the global human population, extended over approximately one-quarter land surface on the Earth. The lakes originated due to the glaciers’ retreating and situated above 3500 m are designated as glacial lakes [1]. Several glacier-fed lakes or glacial lakes are enriching in The Garhwal Himalaya above an altitude of more than 3500 m above mean sea level (AMSL). The mountain lakes show a higher sedimentation rate since they are generally encircled by steep inclines and the dissolved materials straightforwardly transport to the lake because of water, occasional variations in the diverse plant canopy, and later formative exercises [2, 3]. The higher sedimen- tation rates have diminished the existence of many small lakes of Himalaya and other Indian locales and a few lakes have arrived at the skirt of eradication [4, 5]. Particularly, the lakes from the lower region locale of the Lesser Hima- layan, where the vast majority of the lithology is vulner- able to disintegration and displays a higher sedimentation rate [6]. Nonetheless, the sedimentation rate changes from lake to lake and it relies upon a few elements like encom- passing lithology, common and anthropogenic exercises. Subsequently, the investigation of sediment rate in the Himalayan lakes is noteworthy. As the amount of space available for sediments to accumulate increases, the sedi- mentary record forms [7]. Hence, sedimentation is one of the serious issues that diminish the profundity and size of these lakes [8–19]. The high sedimentation rate has reduced the adequacy of a few small lakes and numerous others are contracting at a startling rate. The information on the exact sedimentation rate and its causes are of the most extreme signifcance for appropriate management of lakes and future planning [20]. To estimate the sedimentation rate, the unsupported 210 Pb is being estimated by subtracting the activity of 226 Ra from the total 210 Pb activity as 226 Ra and 210 Pb (supported) are in secular equilibrium [21, 22]. The anthropogenic 137 Cs, a half-life of 30.2 credited to the atmosphere by the rate of atomic weapons tests, occurred during the 1950s and 1960s and bringing about a most extreme fallout in 1963 [23–25]. Hence, the highest peak of 137 Cs activity in the sediment core profle signifes the particular discharge events. The dispersion of 137 Cs is also related to the Chernobyl mis- hap in 1986 and because of the new accident in April 2011, at Fukushima Daiichi atomic catastrophe occurs in Japan. Much of the time, due to their low concentration or fxa- tion, 137 Cs are scarcely perceived in sediments. This may be due to difusion processes which cause the disparity of residence time in the water column, and the mobility within sediments [26]. * Sivaprakasam Vasudevan devansiva@gmail.com 1 Department of Earth Sciences, Annamalai University, Chidambaram, Tamil Nadu 608002, India