Palaeothermometry of the Middle Würmian (MIS 3) in the Eastern Alps

Palaeoclimate research is essential to our understanding not only of the past but also of the future climate change. Ongoing global warming has greatly increased the interest in the palaeoecology of warm periods in the past, including interstadials during the last glacial cycle, which left their traces in geological records. In this context, the middle part of the last glacial period (referred to as the Middle Würmian in the European Alps; equivalent to Marine Isotope Stage (MIS) 3; ca. 6030 ka) is of special interest. This period was characterized by high-frequency climate variability including interstadials of relatively warm and humid climate and may be a model for the climatic conditions that determined environmental processes during much of the Quaternary. However, the understanding of the palaeoclimate history of the Alps during MIS 3 is still fragmentary, because of the sparse coverage and poor preservation and exposure of geological archives. The question of how warm the Middle Würmian was in the Alps is still under discussion. The main objective of this study is to reconstruct the palaeoclimate in the Eastern Alps during MIS 3. The study will be based on the unique palaeolake sediment sequences formed during MIS 3 and preserved at the Unterangerberg and Baumkirchen sites in the Inn Valley, Austria. To achieve the project goals, a multi-proxy palaeolimnological approach using chironomids and other aquatic invertebrates, pollen, aquatic macrophytes, stable isotopes (d18O) and organic carbon to nitrogen (C/N) ratios, which serve as proxies for climatic and environmental change, will be used. Quantitative estimates of past temperatures and precipitation will be produced by applying numerical approaches to fossil chironomid and pollen records from deposits of these two palaeolakes. Innovative aspects of the project reside essentially in the expected results, which include proxy-based quantitative estimates of MIS 3 climate for the Eastern Alps, where quantitative climate data are entirely lacking for this time interval. This study will offer new insights into the climate history of the region during the prominent period of climate variability in the middle of the last glacial period. Special attention will be paid to the comparison of the climate inferences from this study with other MIS 3 palaeoclimate data from the Greater Alpine region and other regions of Europe. Generating palaeoclimate records for the Alps will provide valuable data for the scientific community in the topical fields of climate modelling to verify the accuracy of climate models aimed at predicting future climate change for the region.