High-resolution profile of radiocaesium deposition in Loch Lomond sediments

A sediment core from the southern basin of freshwater Loch Lomond, Scotland, was thinly sectioned at 3 mm intervals and analysed for radiocaesium, present as a result of fallout from the atmospheric nuclear weapons’ testing programme of the 1950s and 1960s and from the Chernobyl reactor accident of April 1986. The high-resolution sampling enabled much improved resolution of peaks from weapons testing fallout and Chernobyl and led to the estimation of a sedimentation rate (30•9 mg cm-2 y-1) for which the uncertainty was a factor of five times less than that of a previous study based on a 1 cm sampling frequency. Further potential advantages of high-resolution sampling in distinguishing possible influences upon the vertical distribution of radiocaesium in sediments are discussed.