Beryllium 10 in Antarctica over the last seven millennia

Since the first measurements of beryllium 10 ( 10 Be) in ice, in the seventies, numerous profiles of this cosmogenic isotope have been obtained both in Antarctica and Greenland. In this article, we focus on Antarctic data, available at nine different sites, covering a significant part of the Holocene, from 237 to 7101 yr BP. We show that correlating their 10 Be profiles allows to synchronize these ice cores with an excellent accuracy and to document the spatial variability of 10 Be concentration and flux. We then examine how this variability is taken into account by a simulation of 10 Be fallout recently performed with the ECHAM6.3-HAM2.3 model. Except for a systematic underestimation of 10 Be fluxes at high accumulation sites, these simulations are overall very satisfying. Finally the excellent accuracy of synchronisation based on 10 Be profiles allows us to derive an Antarctic stack record over the last seven millennia. The reliability of the new 10 Be stack is demonstrated by its superior correspondence with the accurately dated IntCal20 record based on 14 C in tree rings.