Holocene Paleoenvironmental Change Along the Antarctic Peninsula: A Test of the Bipolar/Solar Signal

DMACK：OPP 9615053 MANLEY：OPP 9615670 Banerjee：OPP 9615695 Dunbar：OPP 9615668 Ishman：OPP 9615669 Leventer：OPP 9714371摘要该奖项支持一项多学科、多机构的努力，以阐明南极半岛在全新世(过去10,000年)期间的详细气候历史。全新世是南极古气候记录中一个重要但往往被忽视的部分，因为全新世气候在几十年到几千年的时间尺度上的自然变异性可以被评估为我们现在的“间冰期”世界的模型。该项目建立在对南极半岛沉积过程、生产力模式和气候制度的十多年前期调查的基础上。这项先前的工作确定了包含过去气候变化的超高分辨率记录的关键地点。这些数据表明，在多世纪和千年时间尺度上运行的太阳周期是融水生产和古生产力的重要调节因素。这些海洋记录可以与格陵兰岛和南极洲的冰芯记录相关联。该项目将重点研究帕尔默深部地区的沉积物扩散模式。其目的是了解现代气候和海洋系统与沉积物分布之间目前的联系。特别是，还需要关于海冰对生物沉积物和陆源沉积物分布的影响的补充资料。将使用各种抓取取样和取心设备采集沉积物样本。分析工作将包括使用加速器质谱仪对表层沉积物进行碳14测年，以及标准沉积学、微古生物学和磁性粒度分析。这种多参数方法是提取海洋沉积岩芯中古气候信号的最有效方法。另外两项目标是在拉勒曼德峡湾的穆勒冰架前部署沉积物捕捉器，并结合由联合海洋研究所资助的场地扩建工作开展地震反射工作。沉积物捕集器工作的目标是解决冰架崩解线附近的沙子输送和沉积是否是由融化水过程或风沙过程引起的。此外，还将调查海冰状况与初级生产力之间的关系。一系列跨越帕尔默深盆地的地震测线的收集将完全解决声学基底的深度问题。这个项目的调查人员都有多年在高纬度环境下工作的经验，这为及时完成该项目提供了一个有效的团队。本科生、研究生和研究生将参与项目的所有阶段，以使教育目标与项目的研究目标同步实现。

Domack: OPP 9615053 Manley: OPP 9615670 Banerjee: OPP 9615695 Dunbar: OPP 9615668 Ishman: OPP 9615669 Leventer: OPP 9714371 Abstract This award supports a multi-disciplinary, multi-institutional effort to elucidate the detailed climate history of the Antarctic Peninsula during the Holocene epoch (the last 10,000 years). The Holocene is an important, but often overlooked, portion of the Antarctic paleoclimatic record because natural variability in Holocene climate on time scales of decades to millennia can be evaluated as a model for our present "interglacial" world. This project builds on over ten years of prior investigation into the depositional processes, productivity patterns and climate regime of the Antarctic Peninsula. This previous work identified key locations that contain ultra-high resolution records of past climatic variation. These data indicate that solar cycles operating on multi-century and millennial time scales are important regulators of meltwater production and paleoproductivity. These marine records can be correlated with ice core records in Greenland and Antarctica. This project will focus on sediment dispersal patterns across the Palmer Deep region. The objective is to understand the present links between the modern climatic and oceanographic systems and sediment distribution. In particular, additional information is needed regarding the influence of sea ice on the distribution of both biogenic and terrigenous sediment distribution. Sediment samples will be collected with a variety of grab sampling and coring devices. Analytical work will include carbon-14 dating of surface sediments using accellerator mass spectrometry and standard sedimentologic, micropaleontologic and magnetic granulometric analyses. This multiparameter approach is the most effective way to extract the paleoclimatic signals contained in the marine sediment cores. Two additional objectives are the deployment of sediment traps in front of the Muller Ice Shelf in Lallemand Fjord and seismic reflection work in conjunction with site augmentation funded through the Joint Oceanographic Institute. The goal of sediment trap work is to address whether sand transport and deposition adjacent to the ice shelf calving line results from meltwater or aeolian processes. In addition, the relationship between sea ice conditions and primary productivity will be investigated. The collection of a short series of seismic lines across the Palmer Deep basins will fully resolve the question of depth to acoustic basement. The combination of investigators on this project, all with many years of experience working in high latitude settings, provides an effective team to complete the project in a timely fashion. A combination of undergraduate, graduate and post-graduate students will be involved in all stages of the project so that educational objectives will be met in-tandem with research goals of the project.