Full Vector Studies of the Last 60 Thousand Years Derived From the East Maui Volcano, Hawaii

对夏威夷东毛伊岛火山过去 6 万年的完整矢量研究

• 批准号: 1015329
• 负责人: Emilio Herrero-Bervera
• 金额: $ 19.35万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-15 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1015329&HistoricalAwards=false
• 关键词: Full; Vector; Studies; Last; 60

The main purpose of the investigation is to study the variation of the ancient magnetic field of the Earth generated at the core of the planet and recorded by lavas erupted from the East Maui Volcano, Hawaii. We are studying variations of the paleofield by sampling ~93 lava flows that span the time rage of 200 to 60,000 years before present with the ultimate goal of understanding how the magnetic field of the Earth has been generated within the interior of the planet. The project involves directional analyses and paleointensity studies in order to achieve determinations of the total field vector for the last 60,000 years. The paleointensity experiments that are being used include the new Multispecimen Parallel Differential method, as well as those using the conventional Thellier-Coe method. The advantage of the new technique is that it represents a reliable way of determine absolute paleointensities that is independent of the domain state of the magnetic minerals. The results of this study will be compared with the paleosecular variation values obtained from coeval lavas elsewhere in the Hawaiian Islands. An important outcome of this study will be further refinement of our knowledge of global geomagnetic intensity variations, which are currently over represented from data from European sites. Improved paleointensity curves are essential for global magnetic field models and for the development of more realistic geodynamo models. They are also important as fundamental constraints for dating methods that use cosmogenic isotopes as 14C, beryllium etc. Detailed and reliable paleointensity curves are also useful as correlation and dating tools in archeology and upper Quaternary geology.The project involves international collaboration with researchers from the Netherlands, and is supporting undergraduate research projects of students at the School of Ocean and Earth Science and Technology of the University of Hawaii at Manoa. The project is contributing to the broadening of participation of underrepresented groups and in supporting research infrastructure.

调查的主要目的是研究地球的古老磁场的变化产生于地球的核心，并记录熔岩喷发从东毛伊岛火山，夏威夷。我们正在研究古磁场的变化，通过采样~93个熔岩流，这些熔岩流跨越了200到60，000年前的时间范围，最终目标是了解地球磁场是如何在地球内部产生的。该项目涉及方向分析和古强度研究，以确定过去60，000年的总场矢量。正在使用的古强度实验包括新的多样本并行差分方法，以及使用传统的Thellier-Coe方法。新技术的优点是，它代表了一种可靠的方法来确定绝对古强度，是独立的域状态的磁性矿物。这项研究的结果将与从夏威夷群岛其他地方的同时代熔岩获得的古长期变化值进行比较。这项研究的一个重要成果将是进一步完善我们对全球地磁强度变化的认识，目前欧洲站点的数据过度代表了这一点。改进的古强度曲线对于全球磁场模型和开发更现实的地球发电机模型至关重要。它们也是使用宇宙成因同位素（如14 C、铍等）测年方法的重要基本约束。详细可靠的古强度曲线也可用作考古学和第四纪地质学中的对比和测年工具。该项目涉及与荷兰研究人员的国际合作，并支持马诺阿夏威夷大学海洋和地球科学与技术学院学生的本科生研究项目。该项目有助于扩大代表性不足群体的参与，并支持研究基础设施。