Radiocarbon Calibration and Timescales

This talk will look at recent advances in radiocarbon calibration. One aspect of this is the significant increase in available datasets for the calibration curve over the last year or so, including that of Lake Suigetsu in Japan (Bronk Ramsey et al 2012) and the Hulu Cave speleothem (Southon et al 2012). However, use of these new datasets requires that we think about the relationship between environmental records, the physical constraints on how different environmental archives might behave and the limitations in our different absolute timescales. Similar considerations are also relevant when it comes to calibrating other environmental sequences. Often what we want to do is to compare environmental changes in one part of the world with those in another. The uncertainties in radiocarbon calibration can make this difficult and certainly we need to be able to quantify the uncertainties if we are asking questions about the synchronicity of climate change. Sometimes other information, such as cross-correlating tephra can be useful in resolving these issues. The availability of new data makes all of these issues more pressing but also opens up the opportunity to develop new methods.(author)