Instruments and methods: a novel method for obtaining very large ancient air samples from ablating glacial ice for analyses of methane radiocarbon

Simple item page
dc.contributor.authorPetrenko, VVen_AU
dc.contributor.authorSeveringhaus, JPen_AU
dc.contributor.authorBrook, EJen_AU
dc.contributor.authorMuhle, Jen_AU
dc.contributor.authorHeadly, Men_AU
dc.contributor.authorHarth, CMen_AU
dc.contributor.authorSchaefer, Hen_AU
dc.contributor.authorReeh, Nen_AU
dc.contributor.authorWeiss, RFen_AU
dc.contributor.authorLowe, DCen_AU
dc.contributor.authorSmith, AMen_AU
dc.date.accessioned2009-10-09T04:24:53Zen_AU
dc.date.accessioned2010-04-30T05:03:35Zen_AU
dc.date.available2009-10-09T04:24:53Zen_AU
dc.date.available2010-04-30T05:03:35Zen_AU
dc.date.issued2008-03en_AU
dc.date.statistics2008-03en_AU
dc.description.abstractWe present techniques for obtaining large (similar to 100 L STP) samples of ancient air for analysis of C-14 of methane ((CH4)-C-14) and other trace constituents. Paleoatmospheric (CH4)-C-14 measurements should constrain the fossil fraction of past methane budgets, as well as provide a definitive test of methane clathrate involvement in large and rapid methane concentration ([CH4]) increases that accompanied rapid warming events during the last deglaciation. Air dating to the Younger Dryas-Preboreal and Oldest Dryas-Bolling abrupt climatic transitions was obtained by melt extraction from old glacial ice outcropping at an ablation margin in West Greenland. The outcropping ice and occluded air were dated using a combination of delta N-15 of N-2, delta O-18 of O-2, delta O-18(ice) and [CH4] measurements. The [CH4] blank of the melt extractions was <4 ppb. Measurements of delta O-18 and delta N-15 indicated no significant gas isotopic fractionation from handling. Measured Ar/N-2, CFC-11 and CFC-12 in the samples indicated no significant contamination from ambient air. Ar/N-2, Kr/Ar and Xe/Ar ratios in the samples were used to quantify effects of gas dissolution during the melt extractions and correct the sample [CH4]. Corrected [CH4] is elevated over expected values by up to 132 ppb for most samples, suggesting some in situ CH4 production in ice at this site. © 2008, International Glaciological Societyen_AU
dc.identifier.citationPetrenko, V. V., Severinghaus, J. P., Brook, E. J., Muhle, J., Headly, M., Harth, C. M., Schaefer, H., Reeh, N., Weiss, R. F., Lowe, D. C., & Smith, A. M. (2008). Instruments and methods: a novel method for obtaining very large ancient air samples from ablating glacial ice for analyses of methane radiocarbon. Journal of Glaciology, 54(185), 233-244. doi:10.3189/002214308784886135en_AU
dc.identifier.govdoc1233en_AU
dc.identifier.issn0022-1430en_AU
dc.identifier.issue185en_AU
dc.identifier.journaltitleJournal of Glaciologyen_AU
dc.identifier.pagination233-244en_AU
dc.identifier.urihttp://dx.doi.org/10.3189/002214308784886135en_AU
dc.identifier.urihttp://apo.ansto.gov.au/dspace/handle/10238/1992en_AU
dc.identifier.volume54en_AU
dc.language.isoenen_AU
dc.publisherInternational Glaciological Societyen_AU
dc.subjectAir samplersen_AU
dc.subjectMethaneen_AU
dc.subjectIceen_AU
dc.subjectGlaciersen_AU
dc.subjectAiren_AU
dc.subjectIsotope datingen_AU
dc.titleInstruments and methods: a novel method for obtaining very large ancient air samples from ablating glacial ice for analyses of methane radiocarbonen_AU
dc.typeJournal Articleen_AU
Files
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.79 KB
Format:
Plain Text
Description:
Download
Collections
Journal Articles