Radiometric Chronology of Neh–nar Glacier, Kashmir

Abstract Surface and core samples of Neh–nar Glacier in the Kashmir Valley have been analysed for the radionuclides 32 Si. 210 Pb, 40 K, and 137 Cs. The lateral and vertical profiles (at an altitude of about 4 140 m) reveal: (1) 32 Si activity decreasing slowly from the accumulation zone to 4 050 m...

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Bibliographic Details
Published in:Journal of Glaciology
Main Authors: Nijampurkar, V. N., Bhandari, N., Vohra, C. P., Krishnan, V.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1982
Subjects:
Online Access:http://dx.doi.org/10.1017/s0022143000011813
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000011813
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Summary:Abstract Surface and core samples of Neh–nar Glacier in the Kashmir Valley have been analysed for the radionuclides 32 Si. 210 Pb, 40 K, and 137 Cs. The lateral and vertical profiles (at an altitude of about 4 140 m) reveal: (1) 32 Si 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 210 Pb activity in the surface samples. (3)An horizon at between 2 and 3 m depth containing 210 Pb activity above natural levels. This horizon is also associated with 137 Cs 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 2l0 Pb and the old component by 32 Si. 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.