New Bomb Pulse Radiocarbon Records from Annual Tree Rings in the Northern Hemisphere Temperate Region

The “bomb” radiocarbon spike induced by atmospheric nuclear detonations has been reconstructed at a latitude of 40°N by measuring the 14 C content in annual rings of a living pine ( Pinus pinea ) at the Accelerator Mass Spectrometry facility of the University of Lecce. We report how the samples were taken, selected, prepared for analysis, and measured. The results are in good agreement with other data sets available for the Northern Hemisphere temperate regions, showing that a curve for the calibration of 14 C dates, valid for the whole Northern Hemisphere, can be established for the second half of the 20th century.