Abstract

Although the millennial-scale climatic events that characterise the last glacial period are well-documented in a large number of disparate proxy records, the causal mechanisms remain poorly understood. Large dating uncertainties associated with conventional approaches severely limit the integration of these records to test the degree of climatic synchroneity in relation to these short-lived oscillations. One technique that has considerable potential for the synchronisation of different records is tephrochronology. Tephra isochrones displaying distinct geochemical fingerprints and deposited instantaneously following an eruption have the unique advantage of representing fixed time-lines between different proxy records. Here we report on the ongoing work to trace tephra horizons in the Greenland ice-cores that have the potential to enhance the synchronisation of records spanning the last glacial period. Several of the tephras identified coincide with rapid climatic jumps imprinted in the Greenland ice-cores and thus, represent independent constraints that hold considerable promise for assessing lead/lag responses between the Earth’s climatic components. Major and trace element signatures are used to characterise these horizons and independent ice-core age estimates are presented which can be incorporated into building chronological models for other palaeoarchives in which common tephra horizons can be identified. This work falls within the objectives of the SMART (Synchronising MArine and Ice-core Records using Tephrochronology) and the TRACE (Tephra constraints on RApid Cimatic Events) projects.