FATE OF MERCURY IN THE ARCTIC Michael Evan ... - COGCI

Fate of Mercury in the Arctic 79
Figure 15. The atmospheric bomb pulse northernmost northern hemisphere calibration curve from Goodsite et al,
2002, Appendix C.
Peat cores are sliced in 1-centimetre slices. In each slice, a macrofossil of peat moss is removed
and processed for determination of the level of 14 C, expressed as percent modern carbon, pMC, by
accelerator mass spectrometry. As one goes deeper in the profile, 14 C levels rise to a peak of
approximately 180 pMC. This level is where the 14 C bomb pulse peaked in 1963. Levels then begin
to fall until the early 1950’s. There are a couple of features in the curve related to the temporary
stop in testing. Figure 16., page 80, shows that peat profiles from Denmark and Greenland could
reproduce the calibration curve without dampening. Dampening is when the top of the curve is
found to be much lower than 180 pMC.