Environmental and climatic variability during the Middle Würmian in the northern Alps

末次冰期在北半球以Heinrich事件和Dansgaard-Oeschger （D-O）旋回等强烈的气候变化为特征，在高寒地区被称为w<s:1>末次冰期。后者在格陵兰冰芯的同位素变化中得到了很好的记录，并被命名为格陵兰间冰期和间冰期。然而，在格陵兰冰盖之外，对D-O循环的强度及其对环境的影响的研究还不够充分。在阿尔卑斯地区尤其如此，在那里它们主要来自不连续的岩洞同位素记录。在阿尔卑斯山最后一次冰川高峰开始之前，短期气候变化对阿尔卑斯山环境的影响知之甚少。这一时期沉积物序列保存的稀少是造成这一现象的主要原因。在这里启动了ALPWÜRM项目，该项目将研究中期<s:1>时期的气候、植被、动物和环境条件的变化。对德国东南部内阿尔卑斯地区Nesseltalgraben 27米长的沉积物剖面进行的初步调查，出人意料地发现了大量的化石遗迹。这些提供了对距今至少27000年至43000年（未经校准的14C年代）期间环境条件的详细见解，这在北阿尔卑斯山是迄今为止前所未有的。本项目将对已有的沉积学、地球化学和花粉分析进行细化，以高分辨率重建沉积沉积条件和植被变化。在沉积物中被特别保存的介形虫和苔藓组合将被彻底研究。将介形虫瓣和苔藓残体的氧同位素分析结合起来，将为阿尔卑斯地区中温期的温度变化提供额外的信息。将采用多种测年方法，包括放射性碳测年、发光测年和磁地层学，以提供尽可能准确的年龄模型。在项目过程中收集的气候和环境记录最终将与阿尔卑斯地区内外的其他档案的重建进行比较和联系，以达到一致的中期气候和环境重建。该项目将极大地有助于解决以下问题：在最后一次冰川高峰之前，阿尔卑斯山的极端气候波动有多强烈，以及它们对区域生物多样性产生了何种影响。

The last glacial period, which is called Würmian glaciation in the Alpine region, was characterized in the northern hemisphere by strong climate variations such as Heinrich events and Dansgaard-Oeschger (D-O) cycles. The latter are well documented by isotopic variations in Greenland ice cores and named Greenland interstadials and stadials there. Outside of the Greenland ice sheet, the magnitude of the D-O cycles and their impact on the environment, however, are inadequately studied. This is especially true for the Alpine area, where they are mainly reported from discontinuous speleothem isotope records. Very little is known about the impact of short-term climate variability on the Alpine environment right before the start of the last glacial maximum in the Alps. The scarce preservation of sediment sequences from this period is the main cause for it. Here the project ALPWÜRM kicks in, in which the changes of climate, vegetation, fauna and environmental conditions during the middle Würmian shall be examined. Preliminary investigations on a 27 m long sediment profile at the inner-Alpine locality Nesseltalgraben in southeast Germany delivered an unexpected abundance of fossil remains. These provide detailed insights into the environmental conditions of the period from at least about 27,000 to 43,000 years before present (uncalibrated 14C dates), which is so far unprecedented for the Northern Alps. Already existing sedimentological, geochemical and pollen analyses shall be refined in the project in order to reconstruct sedimentary deposition conditions and vegetational changes in high resolution. Ostracod and moss assemblages, which are exceptionally preserved in the sediment, will be thoroughly investigated. Oxygen isotope analyses on ostracod valves and moss remains will be combined and will provide additional information on the temperature variations during the Mid-Würmian in the Alpine realm. A multiple dating approach will be applied, including radiocarbon dating, luminescence dating and magnetostratigraphy to provide an age model as exactly as possible. The climate and environmental records collected in the course of the project will ultimately be compared and linked with reconstructions from other archives inside and outside the Alpine realm, in order to reach a consistent climate and environmental reconstruction for the middle Würmian. The project will significantly contribute to the question of how strong the extreme climatic fluctuations in the Alps were before the last glacial maximum and which impact they had on the regional biodiversity.