Drilling in the Holy Lake: On the trail of climate history!

Drilling in the Holy Lake: On the trail of climate history!

Scientists from the Helmholtz Center for Georesearch (GFZ) recently started the underwater drilling project at Holy Lake in Potsdam. This innovative study is carried out from a floating platform where sediment cores are taken from a depth of around 13 meters. The deposits obtained, which contain algae residue, pollen and ash, are considered valuable witnesses of the climate and are analyzed in detail in the laboratory in order to draw conclusions about previous environmental changes. A central goal of the research is to understand how quickly the lake has responded to climate and environmental changes. It is currently unclear whether the dates of the sedimentary deposits extend up to 300 years or even thousands of years into the past, as rbb24 reports.

GFZ scientist Sylvia Pinkerneil emphasizes the importance of these analyses, while Markus Schwab explains that the study results could provide valuable information about human activities and their effects on the ecosystem. In a Jugend forscht project in 2022/23, which took place in collaboration with students from the Bertha-von-Suttner-Gymnasium, it was found that the lake floor, like tree rings, preserves climate data. Students even discovered marble dust in the lake, indicating human interference; the Marble Palace, a Prussian royal palace, was built in the 18th century in the immediate vicinity of the lake.

Sediment archive and climate research

The sediment samples from the Holy Lake are important not only for regional environmental research, but also for global climate research. According to information from GFZ, the project involves the identification of seasonally stratified sediments, also known as varves. These varvae reflect seasonal changes in sediment deposition and are preserved on the lake bottom under conditions of low biological activity. The youngest layers of sedimentary deposits provide information over the last 300 years, while deeper layers could date back up to 10,000 years.

One of the exciting goals of this research is to analyze geochemical signatures that document environmental changes associated with urbanization and parkland reconstruction. The cores are expected to reveal significant climatic phases, including the cold period 8,200 years ago and the Roman and Medieval climate optima, highlighting the complex interactions between human activities and climatic conditions.

A look into the future

The comprehensive analysis of the sediments will not only help to understand climatic developments and their causes, but could also provide useful clues about the settlement history of Potsdam, which dates back to the Mesolithic period. The advancing climate change and its effects on the environment were already the subject of intensive research in the 19th century, when human influences on the climate were investigated in detail. Historically, systematic studies of climate change began by scientists who focused on geological and historical time periods to detect and analyze climate change events, as documented in Wikipedia.

This current research at Heiligen See represents an important step not only in understanding the past, but also in being able to better predict possible future developments in connection with climate change. The comprehensive data collection and the planned 10 meter long sediment profiles could play a decisive role.