CAREER: Probing the connections between mantle convection and oceanic gateways in the North Atlantic using deep-sea drilling

炽热的地幔物质从地球内部深处上升到冰岛下面，形成了一个巨大的羽流，每隔数百万年就会脉动一次。羽流脉动导致了连接格陵兰岛、冰岛和苏格兰的海洋门户高度的变化。在过去的几百万年里，这些通道控制着从挪威海流向大西洋的冷水的数量。该项目将利用海底深处收集的岩心数据，研究北大西洋地区的羽流活动和海洋环流的历史。该项目的成果将直接影响我们对过去海洋环流和气候的认识，这是解决当今社会面临的环境挑战的关键。更广泛的影响包括参与当地教师的研讨会，提供K-12活动，开发第一年的地球系统课程，以及支持博士后学者和研究生。冰岛南部的雷克雅内斯山脊的侧翼位于地球上最大的羽状脊系统之一之上，并被快速积累的等高岩漂移沉积物所覆盖，这些沉积物对邻近深水通道影响的海洋条件很敏感。这种构造提供了一个理想的天然实验室来检验关于地幔动力学、古海洋学和气候之间相互作用的假设。该项目将调查新生代冰岛地幔柱在多大程度上控制了北大西洋的海洋门户和深水循环。在国际海洋发现计划第395次考察期间，在Björn和Gardar contourite漂流点收集的样本和数据为我们提供了一个机会，大大提高了我们对北大西洋地区沉积模式和海洋环流历史的理解。海洋盆地演化的运动学和古测深模型将与沉积物积聚速率和最近钻探的岩心的当前速度估计相结合，作为破译过去海洋环流模式的工具。综合考虑，提出的模型和观测将提供对地球内部、海洋和表面域耦合性质的见解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Hot mantle material rises up beneath Iceland from deep within Earth’s interior forming a giant plume that pulses on timescales of millions of years. Plume pulsing contributes to changes in the height of oceanic gateways that link Greenland, Iceland, and Scotland. These gateways control the amount of cold, deep water that has flowed from the Norwegian Sea to the Atlantic ocean over the past few million years. This project will examine the history of plume activity and ocean circulation in the North Atlantic region using data from rock cores collected deep beneath the seabed. The outcomes of this project will have immediate impact upon our knowledge of past ocean circulation and climate, which is key to addressing the environmental challenges that society is confronting today. Broader impacts include participation in workshops for local teachers, delivery of K-12 activities, development of a first year Earth systems class, and support for a post-doctoral scholar and graduate students.The flanks of Reykjanes Ridge south of Iceland lie above one of Earth’s largest plume-ridge systems, and are covered by rapidly accumulating contourite drift sediments that are sensitive to the oceanographic conditions influenced by adjacent deep-water gateways. This configuration provides an ideal natural laboratory to test hypotheses about the interactions between mantle dynamics, paleoceanography, and climate. This project will investigate the extent to which the Iceland mantle plume has controlled oceanic gateways and deep-water circulation in the North Atlantic Ocean during Cenozoic times. Samples and data collected at sites on Björn and Gardar contourite drifts during International Ocean Discovery Program Expedition 395 provide an opportunity to significantly advance our understanding of the history of sedimentation patterns and ocean circulation across the North Atlantic region. Kinematic and paleobathymetric models for ocean basin evolution will be integrated with sediment accumulation rate and current speed estimates from recently drilled cores, as tools to decipher past ocean circulation patterns. Considered together, the proposed models and observations will provide insights into the coupled nature of Earth’s interior, ocean, and surface domains.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.