Glacial Radiocarbon Constraints from Drake Passage Deep-Sea Corals

德雷克海峡深海珊瑚的冰川放射性碳限制

• 批准号: 0636787
• 负责人: Laura Robinson
• 金额: --
• 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: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0636787&HistoricalAwards=false
• 关键词: Glacial; Radiocarbon; Constraints; Drake; Passage

This project uses radiocarbon in deep-sea corals to understand the Southern Ocean's role in modulating global climate. A key site of deep-water formation, the Southern Ocean is critical to exchange of heat and carbon between the deep-ocean and atmosphere. Changes in it may be linked to low atmospheric CO2 during the last glacial maximum through increased biologic carbon draw down or decreased air-sea CO2 exchange. Testing these hypotheses is challenging because of the scarcity of suitable records of the Southern Ocean's biogeochemistry and circulation. The aragonitic skeletons of deep-sea corals may offer insight because they are well suited for radiocarbon analyses-reflective of the 14C content of the past water column--while also allowing for timing of events through U-series age measurements. Overall, these measurements will put new constraints on the extent of air-sea gas exchange, polar water-column stratification, and the flux of Southern-sourced deep water to the rest of the world's oceans. As a part of this work, new sections of the Drake Passage sea floor will be mapped and imaged, along with the present and past distributions of deep-sea corals and their habitats. A significant broader impact of this work is characterizing the functioning of what may be a key control of atmospheric CO2 content, which could prove important for fully understanding the impacts of continued CO2 emissions and developing mitigation strategies. As well, the work will characterize deep marine ecologies that are poorly understood, but increasingly exploited as fisheries resources.

该项目利用深海珊瑚中的放射性碳来了解南大洋在调节全球气候方面的作用。作为深水形成的关键地点，南大洋对深海和大气之间的热量和碳交换至关重要。它的变化可能与末次冰期最大期的低大气CO2通过增加生物碳消耗或减少海-气CO2交换有关。测试这些假设是具有挑战性的，因为缺乏适当的记录南大洋的地球化学和环流。深海珊瑚的文石骨骼可能提供洞察力，因为它们非常适合放射性碳分析-反映过去水柱的14 C含量-同时还允许通过U系列年龄测量确定事件的时间。总的来说，这些测量将对海气交换、极地水柱分层以及南方来源的深水流向世界其他海洋的程度提出新的限制。作为这项工作的一部分，将绘制德雷克海峡海底新部分的地图和图像，同时沿着深海珊瑚及其生境现在和过去的分布情况。 这项工作的一个重要的更广泛的影响是描述可能是大气二氧化碳含量的关键控制的功能，这可能对充分理解持续二氧化碳排放的影响和制定缓解战略非常重要。这项工作还将描述人们对深海生态了解甚少，但越来越多地作为渔业资源开发的特点。