Full vector paleosecular variation (PSV) recorded on the Koolau Volcano, Oahu, Hawaii during the Matuyama Chron at Makapuu Point (ca. 2.6 to ~2.2 Ma).

古地磁(即化石磁性)数据是了解地磁转变以及由此产生磁场的地球发电机过程的唯一观测来源。由于为了更好地了解地球磁场的产生，需要从火山序列中获得逆转记录，建议在夏威夷瓦胡岛库劳火山的Makapuu点研究一个长序列(约191米)的熔岩，主要目的是研究在几次连续的极性转变之前、期间和之后记录的全部古地磁信号。该剖面涵盖了约41万年的磁场变化，包括研究连续磁场倒转的详细记录，如Gauss-Matuyama、Cryptochron C2r.2r-1和留尼汪亚时的开始，因为该剖面的底部为2.60/-13万年，中部为2.49/-0.07万年，剖面顶部以下约10米，年龄为~219/-12万年。这项为期两年的研究的目标是关于像反转和漂移等时期的场变化的知识，以及与反转之前和之后的关键时间间隔有关，到目前为止，只有少数几个沉积序列记录了2.6M a至~2.012 Ma的时间间隔。反转研究不能脱离周围的极性间隔，到目前为止发表的大多数记录都不足以提供完整的信息。该序列提供了一个特殊的机会来研究包括几个极性间隔的一段时间内的变化，从而记录了不同时间常数上的古场行为。这是提取和提出古田生成的理论和数值模拟的重要约束的基本条件。这项研究将对静磁学、岩石磁学、地磁和物理火山作用等领域产生影响。几名本科生将得到支持，并参与这项研究的所有方面。建议集中在全矢量研究，以确定总场矢量和“稳定”极性的古分子变异(PSV)。这项研究将集中于极性的连续周期及其相关的逆转。古强度实验将使用Thellier-Coe的一个版本以及不同的PTRM“多样本”方法进行。PIS制定了严格的标准，以丢弃受磁性矿物转变影响的样品，以及涉及多域颗粒的磁化成分。重要的是要处理依赖于每流至少5至8次测定的古强度值，以便进行适当的统计处理。考虑到古强度研究的耗时方面，预计需要两年的时间来实现这项建议的目标，包括再进行10次放射性40Ar/39Ar年龄测定。首席调查员和四名本科生将实施整个研究项目。本科生的参与将是这个项目的优先事项，从田野调查、实验室工作、分析和结果发布。数据将通过出版物和网络以及社区维护的古地磁和地质年代学数据库进行传播。该项目将提供刺激，以维持在密歇根大学和稀有气体实验室的古地磁操作。在大学。威斯康星大学麦迪逊分校，这两所学校都有来自世界各地的学生和研究人员。

Paleomagnetic (i.e. fossil magnetism) data are the unique source of observations to understand the geomagnetic transitions and hence the geodynamo processes involved in field generation. Due to the fact that there is a need to obtain reversal records from volcanic sequences in order to have a better understanding of the generation of the Earth's magnetic field, it is proposed to study a long sequence (about ~191 meters) of lavas from the island Oahu, Hawaii at a site known as Makapuu Point, Koolau Volcano with the main objective of investigating the full range of paleomagnetic signals recorded before during and after several successive polarity transitions. The section covering ~410,000 years of field changes includes the possibility of studying the detailed recording of the successive magnetic field reversals such as the Gauss-Matuyama, Cryptochron C2r.2r-1 and the onset of the Reunion Subchron, since the base of the section is 2.60+/-0.13 million years old, the middle part is 2.49+/-0.07 million years old and about 10 m below the top of the section the age is ~2.19+/-0.12 million years old. The objectives of this 2 year research study are related to the knowledge of field variations during periods like reversals and excursions and related to the critical time intervals that precede and follow reversals that so far have only been documented from a few sedimentary sequences, for the interval between 2.6 to ~2.012 Ma. Reversal studies cannot be separated from the surrounding polarity intervals and most records published so far were not long enough to provide complete information. The sequence offers the exceptional opportunity to study changes over a time period that includes several polarity intervals and thus documents the paleofield behavior over various time constants. This is a basic condition to extract and bring up significant constraints for the theoretical and numerical modeling of the generation of the paleofield. This research will have impacts on field like magnetostatigraphy, rock magnetism, geomagnetism and physical volcanism. Several undergraduate students will be supported and involved in all aspects of the research.The proposal is focused on full vector studies in order to determine the total field vector and Paleosecular Variation (PSV) of the "stable" polarities. The study will focus on the successive periods of polarity and their associated reversals. The paleointensity experiments will be conducted using a version of the Thellier-Coe as well as the differential pTRM "multi-specimen" methods. The PIs have imposed severe criteria to discard samples affected by magneto-mineralogical transformations and with magnetization components involving multi-domain grains. It is important to deal with paleointensity values that rely on a minimum number of 5 to 8 determinations per flow in order to perform suitable statistical treatment. Given the time consuming aspect of paleointensity studies, a two-year period is envisaged to achieve the goals of this proposal including 10 more radiometric 40Ar/39Ar age determinations. The principal investigator and four undergraduate students will carry out the entire research project. The involvement of undergraduate students will be a priority in this project, from fieldwork, laboratory work, analysis and publication of the results. Data will be disseminated through publication and on the web and community maintained paleomagnetic and geochronologic databases. This project will provide the stimulus to maintain the paleomagnetics operation at UH and the Rare Gas Lab. at the Univ. of Wisconsin at Madison both of which are used by a diverse group of students and researchers from all over the world.