Welcome to VARDA

The Varved Sediments Database (VARDA) provides standardized proxy records from annually resolved lake archives. All proxy records offer full quantification of age-uncertainty from state of the art age-depth modeling routines. VARDA is a service provided by the Helmholtz Centre Potsdam German Research Centre for Geosciences (GFZ) and is funded by the PalMod initiative.

PalMod — Paleo Modeling

PalMod is funded by the German Federal Ministry of Education and Science (BMBF) to examine climate system dynamics and variability during the last glacial cycle. One key aspect is to identify and quantify the relative contributions of the fundamental processes that determined the Earth’s climate trajectory and variability during the last glacial cycle. Using comprehensive Earth System Models (ESM) this consortium aims at simulating the climate from the peak of the last interglacial (the Eemian warm period) up to the present, including its changing variability. The research will assess possible future climate trajectories beyond this century with sophisticated ESMs tested this way.

GFZ — Climate Dynamics and Landscape Evolution

We investigate climate change in the geological and historical past and its impacts on the human habitat as well as past changes in the Earth’s magnetic field. A primary concern of our research are particularly rapid climate changes that occurred within a few years or decades. Therefore, we exploit high-resolution terrestrial geo-archives such as annually laminated (varved) lake sediments and tree rings. A crucial part of our approach is to date our archives precisely and accurately as an important basis for reliable reconstructions of changes in the past.
New datasets added16 November 2020

Thanks to the efforts of Alicja Bonk et al. 2020 and Daniela Müller et al. 2020, varve chronologies, varve thickness and 14C datasets from lake Gosciaz in Poland are now available on our platform.

A swift introduction to VARDA27 October 2020

Cécile Blanchet has published an article on her personal website that gives a brief description of our ongoing project.

A detailed report on VARDA25 September 2020

We’re pleased to announce the final release of our paper in the data publishing journal Earth System Science Data (ESSD). In this paper, we report in detail on our data mining and compilation strategies, the software design and the provided datasets effective by 26 July 2020.

New datasets added11 June 2020

Thanks to the efforts of Julia Kalanke et al. 2020, varve chronologies, varve thickness and 14C datasets from lake Chatyr Kol in Kyrgyzstan are now available on our platform.

Released version 1.0.022 November 2019

This version enables open access to the compiled datasets, including varve chronologies, varve thickness records, tephra layers and radiocarbon measurements. More paleoclimate proxies will be integrated in future updates. We will keep you posted about further additions and developments here, on this page.

Application features provided:

  • Index and map locations of varved lakes
  • Search filters: continent, country, lake, age, tephra
  • Detailed view of lakes and datasets
  • Simple form for contacting the team

Compiled datasets included:

  • Radiocarbon dating: 96
  • Tephra layers: 45
  • Varve chronologies: 64
  • Varve thickness records: 50
  • Total datasets: 255
  • Sampled lakes: 89