A tephra lattice for Greenland and a reconstruction of volcanic events spanning 25–45 ka b2k

• Main Authors: Abbott, P.M., Schüpbach, S., Svensson, A., Seierstad, I.K., Bourne, A.J., Cook, E., Steffensen, J.P., Davies, S.M., Fischer, H.
• Format: Text
• Language: English
• Published: Pergamon 2015
• Subjects: 530 Physics; Greenland; Katla; Dye 3; Dye-3; Greenland ice cores; GRIP; ice core; Iceland; NGRIP; North Atlantic
• Online Access: https://dx.doi.org/10.7892/boris.70071; http://boris.unibe.ch/70071/

Tephra layers preserved within the Greenland ice-cores are crucial for the independent synchronisation of these high-resolution records to other palaeoclimatic archives. Here we present a new and detailed tephrochronological framework for the time period 25,000 e 45,000 a b2k that brings together results from 4 deep Greenland ice-cores. In total, 99 tephra deposits, the majority of which are preserved as cryptotephra, are described from the NGRIP, NEEM, GRIP and DYE-3 records. The major element signatures of single glass shards within these deposits indicate that 93 are basaltic in composition all originating from Iceland. Specifically, 43 originate from Grimsv € otn, 20 are thought to be sourced from the Katla volcanic system and 17 show affinity to the Kverkfj € oll system. Robust geochemical characterisations, independent ages derived from the GICC05 ice-core chronology, and the stratigraphic positions of these deposits relative to the Dansgaard-Oeschger climate events represent a key framework that provides new information on the frequency and nature of volcanic events in the North Atlantic region between GS-3 and GI-12. Of particular importance are 19 tephra deposits that lie on the rapid climatic transitions that punctuate the last glacial period. This framework of well-constrained, time-synchronous tie-lines represents an important step towards the independent synchronisation of marine, terrestrial and ice-core records from the North Atlantic region, in order to assess the phasing of rapid climatic changes during the last glacial period.