239,240Pu and 236U records of an ice core from the eastern Tien Shan (Central Asia)
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 c...
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| Format: | Article |
| Language: | English |
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Cambridge University Press
2017-10-01
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| Series: | Journal of Glaciology |
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| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143017000594/type/journal_article |
| _version_ | 1827994506346102784 |
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| author | CHAOMIN WANG SHUGUI HOU HONGXI PANG YAPING LIU HEINZ WALTER GÄGGELER MARCUS CHRISTL HANS-ARNO SYNAL |
| author_facet | CHAOMIN WANG SHUGUI HOU HONGXI PANG YAPING LIU HEINZ WALTER GÄGGELER MARCUS CHRISTL HANS-ARNO SYNAL |
| author_sort | CHAOMIN WANG |
| collection | DOAJ |
| description | 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 defining the start of the Anthropocene. 236U is a rather new environmental tracer, while little is known about its global fallout from NWT. The observed deposition flux of 236U during NWT amounts to 3.5 × 108 atoms·cm−2 at the drill site. The average 236U/239Pu ratio of 0.27 ± 0.09 is in good agreement with literature values from global fallout. |
| first_indexed | 2024-04-10T04:40:59Z |
| format | Article |
| id | doaj.art-a2fed532982c42fc908222730b6a03e5 |
| institution | Directory Open Access Journal |
| issn | 0022-1430 1727-5652 |
| language | English |
| last_indexed | 2024-04-10T04:40:59Z |
| publishDate | 2017-10-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj.art-a2fed532982c42fc908222730b6a03e52023-03-09T12:40:28ZengCambridge University PressJournal of Glaciology0022-14301727-56522017-10-016392993510.1017/jog.2017.59239,240Pu and 236U records of an ice core from the eastern Tien Shan (Central Asia)CHAOMIN WANG0SHUGUI HOU1HONGXI PANG2YAPING LIU3HEINZ WALTER GÄGGELER4MARCUS CHRISTL5HANS-ARNO SYNAL6School of Geographic and Oceanographic Sciences, Nanjing University, 210023 Nanjing, ChinaSchool of Geographic and Oceanographic Sciences, Nanjing University, 210023 Nanjing, China CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, ChinaSchool of Geographic and Oceanographic Sciences, Nanjing University, 210023 Nanjing, ChinaState Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, 730000 Lanzhou, ChinaPaul Scherrer Institut, 5232 Villigen PSI, Switzerland Department of Chemistry and Biochemistry, University of Bern, 3000 Bern, SwitzerlandLaboratory of Ion Beam Physics, ETH Zürich, 8093 Zürich, SwitzerlandLaboratory of Ion Beam Physics, ETH Zürich, 8093 Zürich, SwitzerlandRadioisotopes (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 defining the start of the Anthropocene. 236U is a rather new environmental tracer, while little is known about its global fallout from NWT. The observed deposition flux of 236U during NWT amounts to 3.5 × 108 atoms·cm−2 at the drill site. The average 236U/239Pu ratio of 0.27 ± 0.09 is in good agreement with literature values from global fallout.https://www.cambridge.org/core/product/identifier/S0022143017000594/type/journal_articleglacier chemistryice coremountain glaciers |
| spellingShingle | CHAOMIN WANG SHUGUI HOU HONGXI PANG YAPING LIU HEINZ WALTER GÄGGELER MARCUS CHRISTL HANS-ARNO SYNAL 239,240Pu and 236U records of an ice core from the eastern Tien Shan (Central Asia) Journal of Glaciology glacier chemistry ice core mountain glaciers |
| title | 239,240Pu and 236U records of an ice core from the eastern Tien Shan (Central Asia) |
| title_full | 239,240Pu and 236U records of an ice core from the eastern Tien Shan (Central Asia) |
| title_fullStr | 239,240Pu and 236U records of an ice core from the eastern Tien Shan (Central Asia) |
| title_full_unstemmed | 239,240Pu and 236U records of an ice core from the eastern Tien Shan (Central Asia) |
| title_short | 239,240Pu and 236U records of an ice core from the eastern Tien Shan (Central Asia) |
| title_sort | 239 240pu and 236u records of an ice core from the eastern tien shan central asia |
| topic | glacier chemistry ice core mountain glaciers |
| url | https://www.cambridge.org/core/product/identifier/S0022143017000594/type/journal_article |
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