A radiocarbon perspective on Greenland ice-core chronologies; can we use ice cores for (super 14) C calibration?

Abstract

Some of the most valuable paleoclimate archives yet recovered are the multi-proxy records from the Greenland GISP2 and GRIP ice cores. The crucial importance of these data arises in part from the strong correlations that exist between the Greenland delta (super 18) O records and isotopic or other proxies in numerous other Northern Hemisphere paleoclimate sequences. These correlations could, in principle, allow layer-counted ice-core chronologies to be transferred to radiocarbondated paleoclimate archives, thus providing a (super 14) C calibration for the Last Glacial Maximum and Isotope Stage 3, back to the instrumental limits of the (super 14) C technique. However, this possibility is confounded by the existence of numerous different chronologies, as opposed to a single (or even a "best") ice-core time scale. This paper reviews how the various chronologies were developed, summarizes the differences between them, and examines ways in which further research may allow a (super 14) C calibration to be established.