Introduction

Exact Chronology of Early Societies (ECHOES) is a 5-year project funded by the European Research Council and based at the University of Groningen. Its central aim is to develop a new approach to radiocarbon dating, one that is accurate to the exact calendar year. The technique will be built on the recent discovery of annual rises, or ‘spikes’, in the concentration of radiocarbon in the atmosphere.

The two spikes found so far occurred in the years 775 and 994 CE, dates that are exactly known because growing trees absorb radiocarbon from the atmosphere, and archives of wood exist within which the age of each tree-ring is precisely known. The cause of the spikes is not yet fully established, but the leading theory is radiation bursts from enormous solar storms. ECHOES aims to find many more of these spikes, and then use them to anchor the timelines of early civilisations such as the Maya and the Egyptians.