Dansgaard/Oeschger Events During Marine Isotope Stage 8

海洋同位素阶段 8 期间的 Dansgaard/Oeschger 事件

• 批准号: 426655162
• 负责人: Privatdozent Dr. Norbert Marwan, since 8/2021
• 金额: --
• 依托单位: Institut für Geologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/426655162?language=en
• 关键词: Dansgaard; Oeschger; Events; During; Marine

In this project, Dansgaard/Oeschger events in the ante penultimate glacial, between ~300 000 to 230 000 years before present, will be identified and the beginning and the duration of each event will be precisely determined. Dansgaard/Oeschger events are short-lasting and repeating warm episodes during the last glacial and seem to follow a certain cyclicity. Originally, they were first observed by fast variations in the stable oxygen isotope composition of ice cores drilled on Greenland. They seem to left hints of their occurrence in various climate archives over large parts of the northern hemisphere. Their finger prints, for example, were also observed in the stable oxygen isotope composition of speleothems from the northern rim of the European Alps over the last 200 000 years. However, currently there is no continental information about the Dansgaard/Oeschger events during the ante penultimate glacial available. Greenland’s ice cores do not cover this time interval since no ice of such age is available. Marine sediments clearly show Dansgaard/Oeschger like pattern in their proxies in this period - however a precise chronology is difficult to obtain from this archive. For this project we have eight stalagmites from the northern Alps which grew during the ante penultimate glacial. Over large time intervals pairs of them grew contemporaneously, so that a high degree of reproducibility is granted. Stable oxygen isotope analyses will provide strong evidence for the existence of these fast climate variations and the uranium-thorium method will be used to establish a precise chronology. Thus, this approach is able to contribute significantly to improve our knowledge of the chronology of these climate variations during the ante penultimate glacial and will help to understand their impacts on climate in the northern hemisphere, their cyclicity and triggering mechanism.

在这个项目中，Dansgaard/Oeschger事件在倒数第二次冰期，约30万至23万年前，现在，将被确定和每个事件的开始和持续时间将被精确地确定。Dansgaard/Oeschger事件是末次冰期持续时间短、重复性强的暖事件，似乎具有一定的周期性。最初，它们是通过在格陵兰岛钻探的冰芯中稳定氧同位素组成的快速变化而首次观察到的。它们似乎在北方大部分地区的各种气候档案中留下了它们发生的线索。例如，在过去的20万年里，在欧洲阿尔卑斯山北方边缘的洞穴沉积物的稳定氧同位素组成中也观察到了他们的指纹。然而，目前还没有关于倒数第二次冰期前Dansgaard/Oeschger事件的大陆信息。格陵兰的冰芯没有覆盖这段时间，因为没有这样年龄的冰。海洋沉积物在这一时期的代用品中清楚地显示出类似于Dansgaard/Oeschger的模式-但是很难从这个档案中获得精确的年代学。在这个项目中，我们有八个来自北方阿尔卑斯山的石笋，它们生长在倒数第二次冰期之前。在很长的时间间隔内，它们的配对同时生长，因此获得了高度的可重复性。稳定氧同位素分析将为这些快速气候变化的存在提供强有力的证据，铀钍法将用于建立精确的年代学。因此，这种方法是能够大大有助于提高我们的知识，这些气候变化的年代学在倒数第二次冰期，并将有助于了解它们对气候的影响，在北方半球，其周期性和触发机制。