Surface and core samples of Neh–nar Glacier in the Kashmir Valley have been analysed for the radionuclides 32Si. 210Pb, 40K, and 137Cs. The lateral and vertical profiles (at an altitude of about 4 140 m) reveal:(1)32Si activity decreasing slowly from the accumulation zone to 4 050 m altitude and then abruptly towards the snout.(2)Five zones of alternating high and low 210Pb activity in the surface samples.(3)An horizon at between 2 and 3 m depth containing 210Pb activity above natural levels. This horizon is also associated with 137Cs and a maximum in total ß activity.The ice samples have been dated on the basis of a simplified two–component model, the “fresh“contribution determined by 2l0Pb and the old component by 32Si. The following conclusions can be drawn from these observations:(1)The model age of the snout ice is c. 850 years.(2)The average rate of ice movement in the lower glacier is about 2 m/year, which compares well with the annual movement rate of 2.65 m/year observed since 1974.
Surface and core samples of Neh–nar Glacier in the Kashmir Valley have been analysed for the radionuclides 32Si. 210Pb, 40K, and 137Cs. The lateral and vertical profiles (at an altitude of about 4 140 m) reveal: (1)32Si activity decreasing slowly from the accumulation zone to 4 050 m altitude and then abruptly towards the snout. (2)Five zones of alternating high and low 210Pb activity in the surface samples. (3)An horizon at between 2 and 3 m depth containing 210Pb activity above natural levels. This horizon is also associated with 137Cs and a maximum in total ß activity. The ice samples have been dated on the basis of a simplified two–component model, the “fresh“contribution determined by 2l0Pb and the old component by 32Si. The following conclusions can be drawn from these observations: (1)The model age of the snout ice is c. 850 years. (2)The average rate of ice movement in the lower glacier is about 2 m/year, which compares well with the annual movement rate of 2.65 m/year observed since 1974.
The surface ice taken from the snout of the Nehnar glacier (Kashmir) in western Himalaya has been dated using radioisotopes 328i and 21OPb to be 500 years. Based on the age distribution of ice and the expected activity of 32Si in the fallout, the average rate of glacier movement over a period of the last few centuries is estimated to be about 6 m/yr. The data obtained on 328i and 210pb activities in the surface ice samples in the ablation zone support our previous observation about the existence of five zones of alternately high and low activity of 210pb, which probably is a consequence of complex dynamics of Nehnar glacier. The vertical profile of 210Pb activity in an ice core correlates directly with the total beta activity. This radioactive horizon at an altitude of 4140 m appears to be located at a depth of 10-12m, which is lower compared to the 2-3 m observed earlier at an altitude of 4150 m.
The ice samples obtained from Dakshin Gangotri, Antarctica show the presence of nuclear debris, attributed mainly to French nuclear explosions. Cosmogenic 7Be occurs at levels of 30 dpm/L. The vertical profile of 6D in 6 m long drill core ranges between-130 and-180%o compared to Standard Mean Ocean Water (SMOW). No systematic change with depth is seen. Small amounts of dust obtained by filtering melt water show presence of metallic spherules. Absence of elements characteristic of meteoritic or cometary debris suggests that most of them are of volcanic or industrial origin.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.