OCE-PRF An integrated study of the closure of the Central American Seaway: Exploring paleoceanography as a tool for broadening participation in ocean sciences

OCE-PRF 对中美洲海道关闭的综合研究：探索古海洋学作为扩大海洋科学参与的工具

• 批准号: 1323649
• 金额: $ 17万
• 依托单位: Waite Amanda J
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1323649&HistoricalAwards=false
• 关键词: OCE; PRF; integrated; study; closure

Overview: The closure of the Central American Seaway (CAS) and resulting Isthmus of Panama have shaped much of our understanding of the adaptation and migration of species between North and South America, as well as the diversification of Pacific and Caribbean marine species. Until recently, the CAS was thought to have closed between approximately 9 and 2 Ma; however, new studies of Panamanian geology suggest the isthmus was sub-aerially exposed by the Early Miocene (approximately 23 Ma). As dramatic global change has been ascribed to the previously accepted timing of this gateway event, the new findings raise many questions regarding the role the closure may have had on ocean circulation, climate, and paleoecology. In this project, the fellow will further investigate the timing and oceanographic impacts of the CAS closure through the development of neodymium (Nd) isotopic records of Caribbean water mass distribution that extend well beyond the presumed Late Miocene closure date, and direct comparison of these data to oceanic model simulations for CAS shoaling. The proposed work will be conducted in the Department of Geological Sciences at the University of Florida (UF) with the sponsorship of Ellen E. Martin, PhD. Intellectual Merit: In order to reconstruct a long-term history of CAS shoaling, Nd-isotopic analyses will be performed on fossil fish teeth recovered from Caribbean Ocean Drilling Program Sites 998, 999, and 1000 for samples extending back to approximately 50 Ma. This record will be used to evaluate the presence of older complete or pulsed closure events predicted by recent geologic findings from Panama, and provide a baseline of conditions prior to shoaling. The fellow hypothesizes that earlier shoaling events produced excursions towards more negative, Atlantic-type, Nd-isotope values that predate those observed in late Miocene sediments; however, these excursions must be transient in nature to reconcile the Pacific signatures documented for the Caribbean between approximately 14 to 10 Ma. The existence of such excursions would corroborate recent studies showing a much earlier rise of the Isthmus of Panama and require a re-evaluation of the associated global ocean circulation, climate, and biogeographic data, while the absence of such excursions would call into question interpretations of earlier complete sub-aerial exposure of Panama. Through the integration of newly generated water mass reconstructions, compilations of marine and terrestrial records from the literature, and modeling of oceanic circulation in collaboration with colleagues, the long-term paleoceanographic shoaling history of the CAS will be documented and its generally accepted associations with global ocean circulation and climate re-evaluated in light of this new information. Broader Impacts: This project will add an oceanographic component to the ongoing efforts of a diverse scientific community studying the rise of the Isthmus via the Panama Canal Project - Partnership for International Research and Education. The fellow will mentor and collaborate with two female minority graduate students pursuing complementary marine research on the project in otherwise terrestrially oriented departments. Two undergraduate students, selected with the goal of broadening participation, will be mentored and involved in all aspects of the proposed research; one of these students will also be supervised in the completion of a related Honors thesis. Additionally, the fellow will design and implement a hands-on introduction to an ocean science module using a major Miocene carbonate dissolution event in the Caribbean as an analog for modern ocean acidification. The module will be integrated into the broader curricula for the California Science, Technology, Engineering and Mathematics (STEM) Teachers Partnership that exposes high school educators, and by extension their students, to unique international science opportunities in order to advance discovery and understanding, and promote a community of teaching, training, and learning. Six teachers from two Santa Cruz school districts with substantial Hispanic populations will participate, allowing for dissemination of ocean awareness to thousands of diverse high school students and encouraging STEM pursuits with a focus on ocean sciences. Finally, broad exposure of the public to ocean science and paleoceanographic research will be achieved via active participation in outreach and education initiatives through the UF, Center for Ocean Sciences Education Excellence (COSEE) Florida, Sea Grant, and the Smithsonian Tropical Research Institute. This participation will include, though not be limited to, development of a paleoceanography booth for the annual "Can you dig it?" event at the Florida Museum of Natural History.

概述：中美洲航道的关闭以及由此造成的巴拿马地峡，在很大程度上影响了我们对南北美洲之间物种适应和迁移以及太平洋和加勒比海洋物种多样化的理解。直到最近，CAS被认为在大约9到2 Ma之间关闭;然而，对巴拿马地质的新研究表明，地峡在早中新世（大约23 Ma）时暴露在空气中。由于剧烈的全球变化被归因于先前接受的这一门户事件的时间，新的发现提出了许多关于关闭可能对海洋环流，气候和古生态学的作用的问题。在这个项目中，该研究员将进一步调查CAS关闭的时间和海洋学影响，通过开发加勒比水团分布的钕（Nd）同位素记录，这些记录远远超出了假定的晚中新世关闭日期，并将这些数据与CAS变浅的海洋模型模拟进行直接比较。拟议的工作将在佛罗里达大学（UF）地质科学系进行，由Ellen E. Martin博士智力优势：为了重建CAS浅滩的长期历史，钕同位素分析将进行从加勒比海钻探计划网站998，999和1000的样品延伸回约50马的化石鱼牙齿。这一记录将用于评估巴拿马最近的地质发现所预测的较早的完全或脉冲闭合事件的存在，并提供变浅前的基线条件。该研究员假设，较早的浅滩事件产生更负的，南极型，钕同位素值，早于晚中新世沉积物中观察到的偏移;然而，这些偏移必须是短暂的性质，以调和太平洋签名记录加勒比之间约14至10马。这种偏移的存在将证实最近的研究表明，巴拿马地峡的上升要早得多，需要重新评估相关的全球海洋环流，气候和海洋地理数据，而没有这种偏移将引起对巴拿马早期完整的空中暴露的解释的质疑。通过整合新生成的水体重建，从文献中汇编海洋和陆地记录，并与同事合作建立海洋环流模型，将记录CAS的长期古海洋学浅滩历史，并根据这一新信息重新评估其与全球海洋环流和气候的普遍接受的关联。更广泛的影响：该项目将为不同科学界通过巴拿马运河项目-国际研究和教育伙伴关系研究地峡隆起的持续努力增加一个海洋学组成部分。该研究员将指导并与两名少数民族女研究生合作，在其他面向陆地的部门就该项目进行补充海洋研究。两名本科生，选择扩大参与的目标，将指导和参与拟议的研究的各个方面;这些学生之一也将在完成相关的荣誉论文的监督。此外，该研究员将设计和实施一个海洋科学模块的实践介绍，使用加勒比地区的一次重大中新世碳酸盐溶解事件作为现代海洋酸化的模拟。该模块将被整合到加州科学、技术、工程和数学（STEM）教师合作伙伴关系的更广泛课程中，该合作伙伴关系使高中教育工作者及其学生接触到独特的国际科学机会，以促进发现和理解，并促进教学、培训和学习的社区。来自两个拥有大量西班牙裔人口的圣克鲁斯学区的六名教师将参加，向数千名不同的高中生传播海洋意识，并鼓励以海洋科学为重点的STEM追求。最后，公众对海洋科学和古海洋学研究的广泛接触将通过佛罗里达大学，海洋科学教育卓越中心（COSEE）佛罗里达，海洋赠款和史密森热带研究所积极参与外联和教育活动来实现。这种参与将包括，但不限于，开发一个古海洋学摊位，为年度“你能挖吗？“活动在佛罗里达自然历史博物馆举行。