Collaborative Research: Coring the Line Islands Ridge for Paleoceanographic Research

合作研究：为古海洋学研究对莱恩群岛山脊取芯

• 批准号: 1157486
• 负责人: Mitchell Lyle
• 金额: $ 3.04万
• 依托单位: Texas A&M University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-15 至 2013-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1157486&HistoricalAwards=false
• 关键词: Collaborative; Research; Coring; Line; Islands

Past changes in the behavior of two key features of the global climate, the Intertropical Convergence Zone (ITCZ) and the El-Nino Southern Oscillation (ENSO), are not clearly understood at present. Continuous records from marine sediments are needed to inform paleoreconstructions of these and other climatic and oceanographic patterns during the Holocene. This project will attempt to acquire such records from the Line Islands Ridge in the Central Tropical Pacific, a key and sensitive location with little in terms of existing samples or data. The Line Islands Ridge is an ideal site to capture paleooceanographic and paleoclimatic changes recorded in sediment for a number of reasons. First, the ITCZ and ENSO are not as susceptible to seasonal or spatial variation in this region as they are elsewhere. In addition, because the Line Islands Ridge is a bathymetric high, the calcium carbonate shells that contain the paleoenvironmental proxy indicators are less likely to be affected by dissolution than in nearby deep ocean settings. Researchers at the Georgia Institute of Technology, Columbia University's Lamont-Doherty Earth Observatory, the Graduate School of Oceanography at the University of Rhode Island, Texas A&M University, Boston University, and the University of California at Santa Cruz will collaborate to conduct a reconnaissance coring survey of the Line Islands Ridge. During a research cruise aboard the R/V Langseth, the PIs will collect bathymetric and geophysical data to constrain optimal coring locations; once optimal locations are established, they will collect a suite of physical samples (an initial gravity core, a CTD/Niskin rosette cast, a piston core, and a multi-core) at each site. Analyses of the cores will include determination of sediment composition using scanning XRF, as well as development of stratigraphic and age models using oxygen isotopes from planktonic foraminifera. Cores and associated data from this reconnaissance effort will be made available to the broader community in order to facilitate future research on paleoclimatic and -oceanographic change over scales of tens to hundreds of thousands of years. Experts in the field foresee using these datasets to better understand past changes in ITCZ and ENSO behavior, sea surface temperature, ocean chemistry, productivity, nutrient and sediment cycling, and eolian dust inputs in the region. Furthermore, these datasets will provide additional opportunities to calibrate paleoclimate models, and may be used to support a geographically overlapping US State Department initiative (Law of the Sea?Extended Continental Shelf program). Additional broader impacts include enhancing scientific infrastructure and disseminating information by adding physical data (cores) to the LDEO sample repository, cataloguing samples through SESAR (System for Earth Sample Registration), and contributing the associated datasets to widely accessible databases (SedDB, NCDC). This project will also involve training for several graduate students. Finally, the multi-faceted approach of this project will provide NSF with an opportunity to evaluate the multi-purpose functionality of the R/V Langseth.

目前尚未清楚地了解了全球气候的两个关键特征的行为变化，受热带融合区（ITCZ）和El-Nino Southern振荡（ENSO）目前尚未清楚地了解。需要来自海洋沉积物的连续记录，以告知全新世期间这些以及其他气候和海洋学模式的古rectosuctions。该项目将尝试从中央热带太平洋的线岛岭获得此类记录，这是一个关键而敏感的位置，在现有样本或数据方面几乎没有。 线岛山脊是捕获沉积物中记录的古海洋摄影和古气候变化的理想场所，原因有很多。首先，ITCZ和ENSO不像其他地方那样容易受到该地区的季节性或空间变化的影响。此外，由于线岛脊是一个测深的高高，因此含有古环境代理指标的碳酸钙壳不受溶解影响的可能性，而不是在附近的深海环境中。哥伦比亚大学佐治亚大学理工学院的研究人员拉蒙特·霍蒂（Lamont-Doherty）地球观测站，德克萨斯州A＆M大学，波士顿大学的罗德岛大学海洋学研究生学院和加利福尼亚大学圣克鲁斯大学威尔将合作进行侦察岛岛岛岛岛的侦察措施。在R/V Langseth的研究中，PIS将收集测深和地球物理数据，以限制最佳的加油位置。建立最佳位置后，它们将在每个位置收集一套物理样品（初始重力核心，CTD/Niskin玫瑰花结ist，活塞芯和多核）。对核心的分析将包括使用扫描XRF确定沉积物组成，以及使用浮游有孔虫中的氧同位素开发地层和年龄模型。 这项侦察工作中的核心和相关数据将提供给更广泛的社区，以促进对古气候和环境学变化的未来研究，超过数十万年限。现场的专家可以预见，使用这些数据集可以更好地了解ITCZ和ENSO行为，海面温度，海洋化学，生产力，营养和沉积物循环以及该地区的Eolian粉尘投入的过去变化。此外，这些数据集将提供额外的机会来校准古气候模型，并可用于支持地理上重叠的美国国务院倡议（海洋法？扩展大陆货架计划）。其他更广泛的影响包括通过向LDEO样品存储库中添加物理数据（核）来增强科学基础架构和传播信息，通过SESAR（用于地球样品注册的系统）对样品进行分类，并贡献相关数据集以广泛访问的数据库（SEDDB，NCDC）。该项目还将涉及几位研究生的培训。最后，该项目的多面方法将为NSF提供评估R/V Langseth的多功能功能的机会。