Volcanic synchronisation between the EPICA Dome C and Vostok ice cores (Antarctica) 0–145 kyr BP

F Parrenin,S O Rasmussen,E Wolff,D Veres,M Severi,J Jouzel,R Udisti,V Lipenkov,J.-R Petit,V Masson-Delmotte,B M Vinther,I Basile-Doelsch,J Schwander

doi:10.5194/cp-8-1031-2012

Abstract

Abstract. This study aims at refining the synchronisation between the EPICA Dome C (EDC) and Vostok ice cores in the time interval 0–145 kyr BP by using the volcanic signatures. 102 common volcanic events were identified by using continuous electrical conductivity (ECM), di-electrical profiling (DEP) and sulfate measurements while trying to minimize the distortion of the glaciological chronologies. This is an update and a continuation of previous works performed over the 0–45 kyr interval that provided 56 tie points to the ice core chronologies (Udisti et al., 2004). This synchronisation will serve to establish Antarctic Ice Core Chronology 2012, the next synchronised Antarctic dating. A change of slope in the EDC-depth/Vostok-depth diagram is probably related to a change of accumulation regime as well as to a change of ice thickness upstream of the Lake Vostok, but we did not invoke any significant temporal change of surface accumulation at EDC relative to Vostok. No significant phase difference is detected between the EDC and Vostok isotopic records, but depth shifts between the Vostok 3G and 5G ice cores prevent from looking at this problem accurately. Three possible candidates for the Toba volcanic super-eruption ~73 kyr ago are suggested in the Vostok and EDC volcanic records. Neither the ECM, DEP nor the sulfate fingerprints for these 3 events are significantly larger than many others in the records.

Highlights

Ice cores drilled in polar areas are natural archives of past environmental and climatic conditions on the Earth
In the following we investigate the offset between European Project for Ice Coring in Antarctica (EPICA) Dome C (EDC)(96,99) and VK-3G isotope records, taking into account the volcanic synchronisation that has been done using the VK-5G ice core
It has been computed as the difference between two EDC3-based Vostok chronologies: one based on volcanic synchronisation (Tables 3 and 4) and one using an isotopic synchronisation based on tie points where the isotopic slope changes abruptly (Table 5)

Summary

Introduction

Ice cores drilled in polar areas are natural archives of past environmental and climatic conditions on the Earth. They can reflect past atmospheric composition and climatic variability for time periods spanning up to several hundreds of millennia in Antarctica (Petit et al, 1999; EPICA community members, 2004; Jouzel et al, 2007) with time-resolution higher than annual for at least the last 60 kyr in some Greenland sites (Vinther et al, 2006; Svensson et al, 2008). Waelbroeck et al, 1995; Parrenin et al, 2004; Dreyfus et al, 2007; Kawamura et al, 2007); (ii) wiggle matching of ice core records to other dated paleo-archives such as ice, marine or terrestrial cores Parrenin et al.: Volcanic synchronisation between the EPICA Dome C and Vostok ice cores

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Discussion

Conclusion