Mode, Variability, and Frequency of Global Neogene Climate Change: The Role of the Southern Ocean

本项目是对古气候变化的研究， 中新世晚期以来的南大洋（最近的1000万次 年），通过检查气候敏感参数 从威德尔海东北部获得的未受干扰的活塞岩心中， 大洋钻探计划第114航次 在该站点进行岩心回收 几乎是连续的，并且已经产生了详细的磁性。 650万年前的地层学，所以准确的 可以预期观察到的事件的日期。 确定已经发生的气候变化，并了解 南极海流系统对这些变化的反应是 海洋古环境研究的主要目标。 等 了解是基于对沉积作用的详细研究 该地区的历史，其中包括现代表面的位置 和底部电流路径，检查紧密间隔的样品 高质量的沉积物岩心，以及 环境事件。 与气候有关的参数包括稳定同位素， %的碳酸盐和有机物质，硅鞭藻，和 放射虫普查数据。 古温度估计将由 硅藻组合，N.厚皮螺旋比率和硅鞭藻 物种比例这些方法在应用于 在亚南极地区的时间框架稍晚。

This project is an investigation into the paleoclimatic variations of The Southern Ocean since the late Miocene (the most recent 10 million years) through the examination of climatically sensitive parameters from undisturbed piston cores obtained in the northeastern Weddell Sea on Leg 114 of the Ocean Drilling Program. Core recovery at this site was nearly continuous, and has already yielded a detailed magnetic stratigraphy to 6.5 million years before present, so that accurate dating of observed events can be expected. Identifying the climatic changes that have occurred, and understanding the responses of the antarctic current system to these changes is one of the major objectives of marine paleoenvironmental research. Such understanding is based on the detailed study of the sedimentation history of the region, which includes the location of modern surface and bottom current pathways, the examination of closely spaced samples from high quality sediment cores, and the regional correlation of environmental events. The climate related parameters to be measured include stable isotopes, percent carbonate and organic matter, silicoflagellates, and radiolarian census data. Paleotemperature estimates will be made from diatom assemblages, N. pachyderma coiling ratios, and silicoflagellate species ratios. These have been quite successful when applied to a somewhat later time frame in the subantarctic region.