Tephra data from varved lakes of the Last Glacial–Interglacial Transition: towards a global inventory and better chronologies on the Varved Sediments Database (VARDA)

Abstract

The Varved Sediments Database (VARDA) was launched in 2020 and aimed to establish a community database for annually resolved chronological archives with their associated high-resolution proxy records. This resource would support reproducibility through accessible data for the paleoclimate and modelling communities. In this paper, VARDA has been extended by a dataset of European tephra geochemical data and metadata to enable the synchronisation of varve records during the Last Glacial–Interglacial Transition (LGIT; here defined as 25 to 8 ka; Beckett et al., 2022). Geochemical data from 49 known individual tephra layers across 19 lake records have been included, with Lago di Grande Monticchio being the single biggest contributor of geochemical data with 28 tephra layers. The Vedde Ash and Laacher See tephra are the most common layers found in six different records. This highlights the potential of refining the absolute age estimates for these tephra layers using varve chronologies and for synchronising regional paleoclimate archives. This is the first stage in a 5-year plan funded by the Past Global Changes (PAGES) Data Stewardship Scholarship to incorporate a global dataset of tephra geochemical data into varve records. Further stages of this project will focus on different regions and timescales. Data collated for this project are available open access at https://doi.org/10.5880/fidgeo.2023.015 (Beckett et al., 2022).