RUI: The Laschamp and Mono Lake Excursions in High Deposition Rate Sediments from Summer Lake, Oregon, USA

RUI：来自美国俄勒冈州萨默湖的高沉积率沉积物中的拉尚和莫诺湖游览

• 批准号: 0911351
• 负责人: Robert Negrini
• 金额: $ 18.34万
• 依托单位: California State University-Bakersfield
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0911351&HistoricalAwards=false
• 关键词: RUI; Laschamp; Mono; Lake; Excursions

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The focus of this project is the recovery of a high-fidelity record of the Earth's magnetic field from ~60,000 to 20,00 years ago. Such records are essential toward a better understanding of the unusually unstable and weak field characterizing this time period. In particular they are necessary to test the proposed geographic distribution, cause, and very existence of two magnetic "excursions" (extreme departures of the magnetic field from its normal state) that likely occurred approximately 41,000 and 34,000 years ago. Because this unusual magnetic field behavior is in principle recorded simultaneously in both marine and nonmarine environments, it can be used as an independent dating method for comparing paleoclimate events from both environments thus leading to confirmation or invalidation of proposed climate connections between the oceans, continents, and atmosphere. Furthermore, because the strength of the magnetic field impacts the production of radiocarbon in the atmosphere, a better understanding of the magnetic field can lead to improved calibrations of radiocarbon dates, the type of corrections that recently resulted in revising our knowledge of interactions between Neanderthals and humans between 40,000 and 30,000 years ago. The research also investigates the usefulness of a lake-level (hence, climate) indicator based on varying magnetic mineral concentration in response to changing lake chemistry with lake depth. The scientific goals of the proposed research are the following: 1) test the hypothesis that the Laschamp and Mono Lake Excursions were separate geomagnetic events that occurred ~40,000 and 34,000 years ago, respectively, 2) constrain the spatial and temporal limits of these records as chronostratigraphic signals and as data for testing geomagnetic field models, and 3) test models of titanomagnetite concentration as an indicator of lake-level change. Several undergraduates and one or two Masters-level graduate students will be substantively engaged in this research. Because CSUB is a teaching university with Hispanic Serving Institution status, both sets of students will be recruited from an ethnically diverse population that is underrepresented in the science disciplines; thus, the project will broaden participation of underrepresented groups in the earth sciences. All of the students will have the opportunity to work at a collaborative, Tier 1 research university for part of their research and/or to present their research at meetings of major scientific societies. The core materials will be rich in paleoclimate indicators thereby fostering future projects for up to a dozen students as part of senior research projects required of all CSUB seniors. Finally, hundreds of general education students and teachers in training will be given updates on this research through lectures and lab exercises by both principal investigators.

该奖项是根据2009年美国复苏和再投资法案(公法111-5)资助的。该项目的重点是恢复约60,000至20，00年前地球磁场的高保真记录。这样的记录对于更好地理解这一时期的异常不稳定和弱场是必不可少的。特别是，它们对于测试所提出的地理分布、原因以及是否存在两个可能发生在大约41,000年和34,000年前的磁“漂移”(磁场对其正常状态的极端偏离)是必要的。由于这种不寻常的磁场行为原则上是在海洋和非海洋环境中同时记录的，它可以作为一种独立的测年方法来比较两种环境中的古气候事件，从而导致对海洋、大陆和大气之间所提出的气候联系的确认或无效。此外，由于磁场的强度影响大气中放射性碳的产生，更好地了解磁场可以改进放射性碳年代的校准，这种类型的校正最近导致我们修订了40,000到30,000年前尼安德特人和人类之间相互作用的知识。这项研究还调查了湖面(因此，气候)指示器的有用性，该指示器基于随湖泊深度变化的湖泊化学变化而变化的磁性矿物浓度。这项研究的科学目标如下：1)检验拉尚和莫诺湖漂移是分别发生在约40,000年和34,000年前的地磁事件的假设，2)限制这些记录作为时间地层信号和作为检验地磁场模型的数据的空间和时间限制，以及3)测试钛磁铁矿浓度作为湖平面变化的指示。几名本科生和一到两名硕士研究生将实质性地参与这项研究。由于CSUB是一所具有西班牙裔服务机构地位的教学大学，这两组学生都将从在科学学科中代表性不足的种族多元化人口中招收；因此，该项目将扩大地球科学代表性不足群体的参与。所有学生将有机会在合作的第一级研究型大学工作，进行部分研究和/或在主要科学学会的会议上展示他们的研究成果。核心材料将包含丰富的古气候指标，从而培养多达12名学生的未来项目，作为CSUB所有高年级学生要求的高级研究项目的一部分。最后，数百名正在接受培训的通识教育学生和教师将通过两位主要研究人员的讲座和实验室练习来了解这项研究的最新情况。