With VARDA, we now provide a unique new paleoclimatic database, developed and hosted at the GFZ. It enables the synchronization of climate records from annually deposited sediments in lakes all over the world.

Sediments offer a unique window to look at the climate history of the Earth. Varves are a specific type of sediments often found in lakes, where particles from the environment accumulate seasonally, forming undisturbed annual successions. Thus, these layers allow to reconstruct climatic changes over of thousands of years, while looking at year-to-year fluctuations in the environment, similar to tree rings.

For example, researchers are investigating how long it takes for climatic changes to affect the local environment of a lake. They want to compare such developments at different locations around the world for individual years and thus also develop a global picture from regional findings. To do this, measurement data from all over the world must be synchronised and made available to the research community.

This is the aim of the VARDA (VARved sediments DAtabase) project headed by Arne Ramisch and Achim Brauer from the German Research Centre for Geosciences GFZ in Potsdam, Section 4.3 Climate dynamics and landscape development.

With the support of the BMBF project PalMod, the researchers collect and revise published and unpublished data of such sediment profiles with climate information covering the last ice age cycle, i.e. the last 120,000 years.

The current version of VARDA includes chronological datasets of 190 lakes around the world as well as software tools for working with the data.

VARDA will help paleoclimatologists from all over the world to compare their climatic records to those in the database, grow the corpus of varved records for others to use and thereby advance the understanding of the complex climatic machinery of our planet.

An online tool for accessing the revised data is provided at
https://varve.gfz-potsdam.de/
including links to the original data sources.

A more detailed description of the project can be found on Cécile Blanchet's blog: https://blanchetcecile.wordpress.com/2020/10/27/varda-looking-into-earths-past-climates-one-layer-at-the-time/

The accompanying publication in Earth System Science Data can be found here:
https://essd.copernicus.org/articles/12/2311/2020/

Scientific Contact:

Dr. Arne Ramisch
Climate Dynamics and Landscape Evolution
Helmholtz Centre Potsdam
GFZ German Research Centre for Geosciences
Telegrafenberg
14473 Potsdam
Email: arne.ramisch@gfz-potsdam.de
Phone: +49 331 288-1300

Dr. Cécile Blanchet
Climate Dynamics and Landscape Evolution
Helmholtz Centre Potsdam
GFZ German Research Centre for Geosciences
Telegrafenberg
14473 Potsdam
Email: cecile.blanchet@gfz-potsdam.de
Phone: +49 331 288-1355

Prof. Dr. Achim Brauer
Climate Dynamics and Landscape Evolution
Helmholtz Centre Potsdam
GFZ German Research Centre for Geosciences
Telegrafenberg
14473 Potsdam
Email: achim.brauer@gfz-potsdam.de
Phone: +49 331 288-1330