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

Fate of Mercury in the Arctic 82
After coring, analysis showed that the Danish core had been disturbed by peat cutting from
during WWII and prior, so it is difficult to conclusively interpret the profile. It is however evident
that pre-industrial levels were much lower than post WWII levels. It is difficult to find a non-
disturbed location in Denmark since surface signs are not always evident, and historical records of
peat digging not always complete.
In both cores, the error associated with the Hg accumulation is calculated to be 21%, based on
conservative estimates of the errors associated with the 14 C bomb pulse curve age dates, ca. 5%; Hg
concentrations, ca. 5%; and bulk density measurements, ca. 20%.
One would expect the bulk density to increase rather smoothly with depth in the core as the
peat becomes more humified and compacted under its own weight. However, in practice, bulk
density determination now introduces the greatest source of error into accumulation determination
as seen from the variation in the bulk density as shown in Figure’s 17 a and b, page 83, and the
error calculation shown above.