When combined with data from tree-ring records, stalagmites can open up a unique archive to study natural climate fluctuations across hundreds of years, a research team including geoscientists from Heidelberg University and the Karlsruhe Institute of Technology have demonstrated.
When combined with data from tree-ring records, stalagmites can open up a unique archive to study natural climate fluctuations across hundreds of years, a research team including geoscientists from Heidelberg University and the Karlsruhe Institute of Technology have demonstrated. The researchers analysed the isotopic composition of oxygen in a stalagmite formed from calcareous water in a cave in southern Germany. In conjunction with the data acquired from tree rings, they were able to reconstruct short-term climate fluctuations over centuries and correlate them with historically documented environmental events.
Until now, short-term climate fluctuations over hundreds of years could be analysed only by means of tree-ring records by combining independent measurements from a number of studies, explains geoscientist Dr Tobias Kluge of the Karlsruhe Institute of Technology (KIT). The size of the tree rings, which varies by a few millimetres, provides information on the dynamics of seasonal precipitation, in turn pointing to climatic conditions in the specific growth period. According to Dr Kluge, summers with heavy rainfall are expected particularly in cold years, whereas very wet winters are expected in warm years.
In contrast to tree rings, stalagmites have only been used in exceptional cases to systematically measure climate data and their annual variations. The decisive factor is the rainwater infiltrating a cave, whose dissolved lime forms the stalagmites. This water comes from local precipitation in the cold and warm seasons, and each is characterised by a special isotopic composition of oxygen. From this, analyses can be derived indicating whether and in which years winter or summer precipitation dominated.
Read more at Heidelberg University
Photo Credit: John-Silver via Pixabay
