A study of the Suess effect using a raised peat bog as historical archive

Abstract

The radiocarbon content in a peat core from Gävle, Sweden, 61.0 oN, 17.0 oE, has been studied. This is a raised peat bog which only receives material from atmospheric deposition. There has been an increased use of fossil fuels by industries and also locally by transports and heating of domestic buildings. There has been fallout of 14C from nuclear tests during the 1950ies and 1960ies and also from the Chernobyl accident in 1986. There is also emission of 14C from nuclear facilities. The 14C/12C ratio from the Chernobyl accident is unclear since it was a graphite moderated reactor and the graphite was burning. The core was sampled in 2008 and was previously dated using the 210Pb method, giving a growth rate of 0.15 mm/yr. The top 21 cm have been analyzed to obtain radiocarbon content by Accelerator Mass Spectrometry (AMS) at the Centro Nacional de Aceleradores (CNA), Seville Spain. Using 0.5 cm samples, information about the last 140 years could be obtained with resolution better than 4 years. Results show a clear depletion of F14C levels in the area, the so called SUESS effect with maximum levels of only F14C=1.2333±0.0043, and the absence of a clear nuclear tests peak.