Pu-239,Pu-240 and U-236 records of an ice core from the eastern Tien Shan (Central Asia) ...

• Main Authors: Wang, Chaomin, Hou, Shugui, Pang, Hongxi, Liu, Yaping, Gaggeler, Heinz W., Christl, Marcus, Synal, Hans-Arno
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2017
• Subjects: glacier chemistry; ice core; mountain glaciers
• Online Access: https://dx.doi.org/10.3929/ethz-b-000227394; http://hdl.handle.net/20.500.11850/227394

Radioisotopes (239Pu, 240Pu, 236U) formed during atmospheric nuclear weapons testing (NWT) can be used for dating and therefore be applied as markers of the beginning of the Anthropocene Epoch. Moreover, 240Pu/239Pu ratios enable source identification (general fallout, local emission sources). Ice core segments from a 57.6 m ice core to bedrock from eastern Tien Shan, China were selected for 239,240Pu and 236U analyses by using compact low-energy accelerator mass spectrometry. The observed 240Pu/239Pu atom ratios were 0.18 ± 0.02, with one exception, indicating global fallout. No evidence for emissions from the nearby local sources Lop Nor was observed. The total deposition rates during NWT for 239Pu and 240Pu amount to 1.55 × 109 atoms·cm−2 and 3.1 × 108 atoms·cm−2, respectively. With the higher undisturbed fallout of 239Pu compared with values reported for glaciers from European Alps at Col du Dome and Colle Gnifetti as well as from the polar region, the eastern Tien Shan glacier would be an ideal site for ... : Journal of Glaciology, 63 (241) ...