Radiocarbon Ventilation Ages and Climate in the Northern Subtropical Atlantic

北亚热带大西洋的放射性碳通风年龄和气候

• 批准号: 0822854
• 负责人: Lloyd Keigwin
• 金额: $ 62.67万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0822854&HistoricalAwards=false
• 关键词: Radiocarbon; Ventilation; Ages; Climate; Northern

This proposal seeks funds to conduct paleo-ocean and paleoclimate studies of deep ocean sediments from high deposition rate sites in the western subtropical North Atlantic. In the first year, research will be conducted on existing samples from Laurentian Fan and new samples will be collected during a three week surveying and coring cruise to locations between Newfoundland and the Mid Atlantic Ridge (MAR). Each location will be sampled with a multicorer, a gravity corer, and a large diameter long piston corer. The underlying theme of this research is to link radiocarbon ventilation ages in the deep ocean, as measured by paired 14C analysis of benthic and planktonic foraminifera, with surface ocean conditions on different spatial and temporal scales across the last 20,000 years. The primary scientific emphasis will be on developing a time series of ocean ventilation for the past several millennia, including the Little Ice Age, and targeting extreme climate events of the past 20,000 years since the end of the ice age. At present, there are insufficient published radiocarbon data to confirm whether or not significant ocean ventilations changes were associated with climate shifts in recent millennia. If the expected results show continuous, systematic changes in ocean ventilation in the recent past, then these results will provide an important boundary condition for understanding how global change and deep ocean circulation are linked. This research will have broad impact through taking teachers to sea and using web-based media to communicate with them and students as the project develops.

本提案寻求资金，对北大西洋副热带西部高沉积速率地点的深海沉积物进行古海洋和古气候研究。在第一年，研究将对Laurentian Fan的现有样本进行研究，并在纽芬兰和大西洋中脊（MAR）之间的位置进行为期三周的测量和取芯巡航期间收集新样本。每个位置将取样与多重覆盖，重力覆盖，和大直径长活塞覆盖。这项研究的基本主题是将深海的放射性碳通风年龄（通过对底栖生物和浮游有孔虫的配对14C分析测量）与过去2万年中不同时空尺度的海洋表面条件联系起来。主要的科学重点将是开发过去几千年的海洋通风时间序列，包括小冰河期，并针对自冰河期结束以来过去2万年的极端气候事件。目前，没有足够的放射性碳公布数据来确认近千年来海洋通风的重大变化是否与气候变化有关。如果预期结果显示在最近的过去，海洋通风发生了连续的、系统的变化，那么这些结果将为理解全球变化和深海环流之间的联系提供一个重要的边界条件。随着项目的发展，本研究将通过将教师带到海上，并利用网络媒体与他们和学生进行交流，从而产生广泛的影响。