"Arctic Ocean Paleoceanography (ArcOP)": Pilot research and lead of IODP Expedition 377(ArcOP-Pilot)

“北冰洋古海洋学（ArcOP）”：IODP 377号探险队的试点研究和领导（ArcOP-Pilot）

• 批准号: 447617953
• 负责人: Professor Dr. Rüdiger Stein
• 金额: --
• 依托单位: Zentrum für Marine Umweltwissenschaften (MARUM)
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/447617953?language=en
• 关键词: Arctic; Ocean; Paleoceanography; ArcOP; Pilot

In the New Proposal, it has been outlined in detail that the Arctic Ocean was/is a key player in the past, present and future global climate/earth system, however, the marine geoscience research in the Arctic lags behind other world oceans, especially from a paleoclimatic perspective. Concerning the reconstruction of the long-term climate history, a breakthrough in Arctic Ocean paleoclimate research was the first scientific drilling in the permanently ice-covered central Arctic Ocean that was carried out during IODP Exp 302 (ACEX) in 2004. The ACEX results were unprecedented and give important insight into the long-term Arctic climate and sea-ice history on its pathway from Greenhouse to Icehouse conditions. However, major questions related to the climate history of the Arctic Ocean during early Cenozoic times remain unanswered, partly due to the major mid-Cenozoic hiatus (or strongly reduced sedimentation rates) and partly to the poor recovery of the ACEX record. Following-up ACEX and its cutting-edge science, a second scientific drilling on Lomonosov Ridge with a focus on the reconstruction of the continuous and complete Cenozoic Arctic Ocean climate history, has been proposed and is now re-scheduled as IODP Exp 377 (“Arctic Ocean Paleoceanography - ArcOP”) for August-September 2022. In this context, the main focus within this DFG project will be (1) to carry out a pilot study on Polarstern sediment cores recovered at or close to the locations of potential IODP 377 drill sites during Exp PS115/2 in 2018, (2) to contribute to the final planning and implementation as well as the lead of IODP Exp 377 (as one of the co-chief scientists), and (3) to document and present first results of the pilot study as well as the IODP expedition during post-cruise meetings and in reports/publications. The pilot study is of major relevance for IODP Exp 377 as already described in the New Proposal:- By combining the Polarstern cores composed of the uppermost undisturbed about 10 m of late Quaternary sediments, and the IODP drill holes in which the uppermost meters are often not well preserved due to drilling disturbances near the water-sediment interface, a unique complete and undisturbed composite sedimentary section representing the early Cenozoic to Recent, will be obtained.- For correlating the Polarstern cores and IODP sites in detail, MSCL-Logging and XRF scanning data (to be determined on selected Polarstern cores following the IODP rules), will be used.- An age model of the Polarstern cores will be developed based on detailed litho-, cyclo-, paleomagneto-, and 230Th-isotope-stratigraphy to be later incorporated into the age model of the IODP Exp 377 sedimentary sequence.- For reconstructing the Quaternary Arctic climate history, a multiproxy approach will be carried out on the Polarstern cores, including the determination of specific biomarkers, mineral assemblages, coarse-fraction composition, grain-size distributions and XRF scanning data.

新提案中详细阐述了北冰洋在过去、现在和未来全球气候/地球系统中的重要作用，但北极海洋地球科学研究相对滞后，尤其是从古气候学的角度。在重建长期气候史方面，北冰洋古气候研究的一个突破是在2004年IODP Exp 302（ACEX）期间在永久冰封的北冰洋中部进行的第一次科学钻探。ACEX的结果是前所未有的，并提供了重要的洞察长期的北极气候和海冰的历史上，其路径从温室到冰室条件。然而，与新生代早期北冰洋气候历史相关的重大问题仍然没有答案，部分原因是新生代中期的重大间断（或沉积速率大幅降低），部分原因是ACEX记录恢复不良。后续ACEX及其前沿科学，即罗蒙诺索夫海岭的第二次科学钻探，重点是重建连续完整的新生代北冰洋气候历史，现已被重新安排为IODP Exp 377（“北冰洋古海洋学- ArcOP”），于2022年8月至9月进行。在这种情况下，DFG项目的主要重点是：（1）在2018年ExpPS 115/2期间，对在潜在IODP 377钻井现场或附近采集的Polarstern沉积物岩心进行试点研究，（2）为最终规划和实施以及IODP Exp 377的领导做出贡献（作为共同首席科学家之一），（3）在航行后会议上和在报告/出版物中记录和介绍试点研究以及海洋学方案考察的初步结果。如新提案中所述，该试点研究与IODP Exp 377具有重大相关性：-通过将由最上部约10 m的未受干扰的晚第四纪沉积物组成的Polarstern岩心与IODP钻孔（由于水-沉积物界面附近的钻探干扰，最上部的米通常未得到良好保存）相结合，将获得代表新生代早期至近代的独特完整和未受干扰的复合沉积剖面。为了将Polarstern岩心和IODP现场详细关联起来，将使用MSCL测井和XRF扫描数据（根据IODP规则对选定的Polarstern岩心进行确定）。Polarstern岩心的年龄模型将根据详细的岩石、旋回、古地磁和230 Th同位素地层学开发，随后将纳入IODP Exp 377沉积序列的年龄模型。为了重建第四纪北极气候史，将对Polarstern岩心进行多代理方法，包括确定具体的生物标志物、矿物组合、粗粒组成、粒度分布和X射线荧光扫描数据。