Iron Age (300-1800 AD) Geomagnetic Paleointensity of Southern Africa

铁器时代（公元 300-1800 年）南部非洲的地磁古强度

• 批准号: 0838185
• 负责人: John Tarduno
• 金额: $ 22万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-01-15 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0838185&HistoricalAwards=false
• 关键词: Iron; Age; 300; 1800; AD

The precipitous decay in the intensity of the Earth's dipole magnetic field since 1840 is a robust feature defined by magnetic observatory data. The drop is related to a low magnetic intensity region called the South Atlantic Anomaly, which may be driven by the growth of a prominent reversed magnetic flux core patch off the coast of South Africa. The magnetic dipole history prior to the era of modern observatory measurements is uncertain because of the near lack of archeomagnetic data from the Southern Hemisphere. A paleointensity record of the geomagnetic field for the Southern Hemisphere is potentially held in Iron Age (300 to 1800 AD) ceramics of southern Africa. The Paleomagnetism Research Group at the University of Rochester is analyzing this record. They are combining these paleointensity data with magnetic directions obtained from analyses of oriented archeological materials and other field strength measures using a new technique (the analysis of single grain pottery temper). The ultimate goal of the project is to use the new magnetic records to test geomagnetic field models and contrasting interpretations of the long-term nature of the modern dipole decrease. A Southern Hemisphere archeomagnetic record is of interest to a broad range of scientists, ranging from those studying processes active in the Earth?s core to those interested in the efficiency of magnetic shielding from solar energetic particles. The investigation involves international collaboration with South African archeologists and geologists. The work incorporates graduate and undergraduate student studies and a small number of K-12 activities. The latter integrate the teaching efforts of the University of Rochester Paleomagnetism Research Group with the Rochester community. Outreach activities also include dissemination of the research results in South Africa. This award is co-funded by NSF's Geophysics Program and the Office of International Science and Engineering.

自1840年以来，地球偶极磁场强度的巨大衰减是由磁性天文台数据定义的强大特征。该下降与称为南大西洋异常的低磁强度区域有关，该区域可能是由南非海岸附近突出的磁通量核心斑块的生长驱动的。 现代天文台测量时代之前的磁偶极子历史尚不确定，因为来自南半球的考古磁数据几乎缺乏。 南半球的地磁领域的古显微记录可能在南部非洲的铁器时代（300至1800年）的陶瓷中持有。罗切斯特大学的古磁研究小组正在分析这一记录。他们将这些古显着性数据与使用新技术（单粒陶器的分析）分析从定向考古材料和其他野外强度测量的分析中获得的磁性方向相结合。 该项目的最终目标是使用新的磁记录测试地磁场模型以及对现代偶极子降低的长期性质的对比解释。南半球的考古磁记录对广泛的科学家来说是感兴趣的，从研究地球核心的那些过程到那些对从太阳能能量颗粒产生的磁性屏蔽效率感兴趣的人。调查涉及与南非考古学家和地质学家的国际合作。这项工作包括研究生和本科生学习以及少量的K-12活动。后者将罗切斯特大学古势研究小组的教学工作与罗切斯特社区结合在一起。 外展活动还包括传播南非的研究结果。该奖项由NSF的地球物理计划和国际科学与工程办公室共同资助。