Abstract The most pronounced climate anomaly of the Holocene was the 8.2 ka cooling event. We present new 230Th/U-ages as well as high-resolution stable isotope and trace element data from three stalagmites from two different cave systems in Germany, which provide important information about the structure and climate variability of the 8.2 ka event in central Europe. In all three speleothems, the 8.2 ka event is clearly recorded as a pronounced negative excursion of the δ18O values and can be divided into a ‘whole event’ and a ‘central event’. All stalagmites show a similar structure of the event with a short negative excursion prior to the ‘central event’, which marks the beginning of the ‘whole event’. The timing and duration of the 8.2 ka event are different for the individual records, which may, however, be related to dating uncertainties. Whereas stalagmite Bu4 from Bunker Cave also shows a negative anomaly in the δ13C values and Mg content during the event, the two speleothems from the Herbstlabyrinth cave system do not show distinct peaks in the other proxies. This may suggest that the speleothem δ18O values recorded in the three stalagmites do not primarily reflect climate change at the cave site, but rather large-scale changes in the North Atlantic. This is supported by comparison with climate modelling data, which suggest that the negative peak in the speleothem δ18O values is mainly due to lower δ18O values of precipitation above the cave and that temperature only played a minor role. Alternatively, the other proxies may not be as sensitive as δ18O values to record this centennial-scale cooling event. This may particularly be the case for speleothem δ13C values as suggested by comparison with a climate modelling study simulating vegetation changes in Europe during the 8.2 ka event. Based on our records, it is not possible to resolve which of these hypotheses is most appropriate, but our multi-proxy dataset shows that regional climate evolution during the event was probably complex, although all δ18O records show a clear negative anomaly.

中文翻译：

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从德国三个洞穴重建的 8.2 ka 事件的气候和结构

摘要 全新世最显着的气候异常是8.2ka变冷事件。我们提供了来自德国两个不同洞穴系统的三个石笋的新 230Th/U 年龄以及高分辨率稳定同位素和微量元素数据，这些数据提供了有关中欧 8.2 ka 事件的结构和气候变异的重要信息。在所有三个洞穴中，8.2 ka 事件被清楚地记录为 δ18O 值的明显负偏移，并且可以分为“整体事件”和“中心事件”。所有石笋都显示出类似的事件结构，在“中心事件”之前有一个短暂的负偏移，这标志着“整个事件”的开始。8.2 ka 事件的时间和持续时间对于个别记录是不同的，但这可能与年代不确定性有关。虽然来自 Bunker Cave 的石笋 Bu4 在事件期间也显示出 δ13C 值和 Mg 含量的负异常，但来自 Herbstlabyrinth 洞穴系统的两个洞穴群在其他代理中没有显示出明显的峰值。这可能表明三个石笋中记录的洞穴洞 δ18O 值主要不是反映洞穴地点的气候变化，而是北大西洋的大规模变化。这得到了与气候模型数据比较的支持，气候模型数据表明洞穴中 δ18O 值的负峰值主要是由于洞穴上方降水的 δ18O 值较低，温度仅起次要作用。或者，其他代理可能不像 δ18O 值那样敏感，无法记录这一百年规模的冷却事件。与模拟 8.2 ka 事件期间欧洲植被变化的气候模型研究相比，洞穴 δ13C 值可能尤其如此。根据我们的记录，无法确定这些假设中的哪一个最合适，但我们的多代理数据集显示事件期间的区域气候演变可能很复杂，尽管所有 δ18O 记录都显示出明显的负异常。