Publication Date:
2009-04-25
Description:
The cause of a large increase of atmospheric methane concentration during the Younger Dryas-Preboreal abrupt climatic transition (approximately 11,600 years ago) has been the subject of much debate. The carbon-14 (14C) content of methane (14CH4) should distinguish between wetland and clathrate contributions to this increase. We present measurements of 14CH4 in glacial ice, targeting this transition, performed by using ice samples obtained from an ablation site in west Greenland. Measured 14CH4 values were higher than predicted under any scenario. Sample 14CH4 appears to be elevated by direct cosmogenic 14C production in ice. 14C of CO was measured to better understand this process and correct the sample 14CH4. Corrected results suggest that wetland sources were likely responsible for the majority of the Younger Dryas-Preboreal CH4 rise.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Petrenko, Vasilii V -- Smith, Andrew M -- Brook, Edward J -- Lowe, Dave -- Riedel, Katja -- Brailsford, Gordon -- Hua, Quan -- Schaefer, Hinrich -- Reeh, Niels -- Weiss, Ray F -- Etheridge, David -- Severinghaus, Jeffrey P -- New York, N.Y. -- Science. 2009 Apr 24;324(5926):506-8. doi: 10.1126/science.1168909.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA. vasilii.petrenko@colorado.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19390044" target="_blank"〉PubMed〈/a〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
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Chemistry and Pharmacology
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Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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