The accumulation of 210Pb at Summit, Greenland since 1855
The decay corrected activity of 210Pb at the time of deposition shows considerable short term variability, but no clear seasonal or annual periodicity. 210Pb activity in surface snow at this site has averaged 0.7 pCi kg-1 since 1927, but the period 1915-1927 is characterized by a steady decline from...
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| Format: | Text |
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University of New Hampshire Scholars' Repository
1992
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| Online Access: | https://scholars.unh.edu/earthsci_facpub/217 https://scholars.unh.edu/cgi/viewcontent.cgi?article=1216&context=earthsci_facpub |
| Summary: | The decay corrected activity of 210Pb at the time of deposition shows considerable short term variability, but no clear seasonal or annual periodicity. 210Pb activity in surface snow at this site has averaged 0.7 pCi kg-1 since 1927, but the period 1915-1927 is characterized by a steady decline from higher levels. The average annual accumulation of 210Pb has markedly declined since at least 1870. Similar observation at Dye 3 suggest that 210Pb accumulation has decreased throughout this century over much of the Greenland Ice Sheet. If the records of 210Pb in the firn of the Greenland Ice Sheet are mainly reflecting the northern hemisphere atmospheric burden of 210Pb, these results will demand careful reassessment of 210Pb-based radiochronologies. -from Author |
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