학술논문
Plutonium from Global Fallout Recorded in an Ice Core from the Belukha Glacier, Siberian Altai.
Document Type
Article
Author
Source
Subject
*NUCLEAR weapons (International law)
*EMISSION standards
*NUCLEAR weapons testing
*SPECTRUM analysis
*NUCLEAR arms control
*PRODUCT management
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Language
ISSN
0013-936X
Abstract
Ice cores from glaciers situated near anthropogenic sources of air pollution provide important archives of the emissions of species with short atmospheric lifetimes. Here we present the history of atmospheric Pu fallout reconstructed from an ice core from the Belukha glacier in the Siberian Altai. Fourteen ice core samples covering the time period 1941-1986 were selected for Pu analysis, chemically processed, and measured using accelerator mass spectrometry. The Pu concentration peaks in 1963, coinciding with the maximum of the nuclear weapons tests and in concordance with the ³H activity concentration peat The shapes of the 239Pu and ³H profiles reflect two main periods of atmospheric nuclear test activity: premoratorium testing before 1958 and postmoratorium testing in 1961 and 1962. Premoratorium tests contribute about 45% of the integrated Pu inventory. The average 240Pu/239Pu isotopic ratio is 0.18 ± 0.05, indicating that a large majority of the Pu in the Belukha glacier originates from global stratospheric fallout rather than from direct tropospheric input. [ABSTRACT FROM AUTHOR]