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- Dahl-Jensen, D., et al.
(author)
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Eemian interglacial reconstructed from a Greenland folded ice core
- 2013
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 493:7433, s. 489-494
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Journal article (peer-reviewed)abstract
- Efforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new North Greenland Eemian Ice Drilling ('NEEM') ice core and show only a modest ice-sheet response to the strong warming in the early Eemian. We reconstructed the Eemian record from folded ice using globally homogeneous parameters known from dated Greenland and Antarctic ice-core records. On the basis of water stable isotopes, NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 +/- 4 degrees Celsius above the mean of the past millennium, followed by a gradual cooling that was probably driven by the decreasing summer insolation. Between 128,000 and 122,000 years ago, the thickness of the northwest Greenland ice sheet decreased by 400 +/- 250 metres, reaching surface elevations 122,000 years ago of 130 +/- 300 metres lower than the present. Extensive surface melt occurred at the NEEM site during the Eemian, a phenomenon witnessed when melt layers formed again at NEEM during the exceptional heat of July 2012. With additional warming, surface melt might become more common in the future.
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2. |
- Pham, M K, et al.
(author)
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A certified reference material for radionuclides in the water sample from Irish Sea (IAEA-443)
- 2011
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In: JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY. - : Springer Science Business Media. - 0236-5731 .- 1588-2780. ; 288:2, s. 603-611
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Journal article (peer-reviewed)abstract
- A new certified reference material (CRM) for radionuclides in sea water from the Irish sea (IAEA-443) is described and the results of the certification process are presented. Ten radionuclides (H-3, K-40, Sr-90, Cs-137, U-234, U-235, U-238, Pu-238, Pu239+240 and Am-241) have been certified, and information values on massic activities with 95% confidence intervals are given for four radionuclides (Th-230, Th-232, Pu-239 and Pu-240). Results for less frequently reported radionuclides (Tc-99, Th-228, Np-237 and Pu-241) are also reported. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in water samples, for the development and validation of analytical methods and for training purposes. The material is available in 5 L units from IAEA (http://nucleus.iaea.org/rpst/index.htm).
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