Collaborative Research: The Holocene paleomagnetic record of the Arctic

合作研究：北极全新世古地磁记录

• 批准号: 0909545
• 负责人: Joseph Stoner
• 金额: $ 40万
• 依托单位: Oregon State University
• 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 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0909545&HistoricalAwards=false
• 关键词: Collaborative; Research; Holocene; paleomagnetic; record

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This award will support a reconstruction of the Holocene paleomagnetic record of the Arctic and investigate linkages with regional climate. The central focus of this project is to recover continuous 3 to 5 m-long sediment cores from lakes in NW and NE Alaska, and the Mackenzie Delta, Banks Island and Victoria Island, Canada. Multiple cores from two similar lake systems at each of the four locations will be recovered. The cores will be the subject of a series of analytical techniques including magnetic, lithostratigraphic, geochemical and biological measurements. The sites selected for study will provide records that extend through the Holocene back as far as 20 ka providing the longest high-resolution Arctic paleomagnetic records to date. Chronologies will be primarily derived by radiocarbon dating using modern AMS C-14 techniques. A series of methods will be used to document the climate history of the region including environmental magnetism, geochemistry, scanning XRF, biogenic silica and a host of biological climate proxies with Canadian collaborators. The paleomagnetic and environmental magnetic records will be studied on multiple cores from each lake by alternating field demagnetization of u-channel samples.The 'Intellectual Merit' of the study lies in the development of a new set of Holocene paleomagnetic observations that will confirm and expand, spatially and temporally, upon previous Arctic paleomagnetic observations and supplement ongoing Arctic and global Holocene paleomagnetic initiatives. The extended Arctic paleomagnetic record will permit direct comparison to marine records from Iceland and those now being developed in the Gulf of Alaska and the Arctic Ocean and Baffin Bay. These new records will permit reconstruction of the Holocene (and possibly beyond) paleomagnetic record of the Arctic, provide constraints necessary to test geomagnetic hypotheses, contribute to the continuing development of an Arctic magneto-stratigraphic network to facilitate dating of marine and terrestrial paleorecords, and provide new constraints on whether the geomagnetic field has a role in the climate system.The 'Broader Impacts' of the study relate to scientific and educational outcomes. Data generated from the study, when combined with results from Phase I and other published studies, will provide a 180° paleomagnetic perspective around the Arctic, documenting past changes and providing paleo-constraints on the future behavior and impacts of the ongoing motion of the north magnetic pole. The data will also help to differentiate the contributions of geomagnetic versus solar control on terrestrial cosmic ray flux and cosmogenic isotope production with practical implications for telecommunications, human health, global ecosystems and climate. Data will be contributed to magIC, sedDB and NOAA paleoclimate databases and used to supplement ongoing spherical harmonic studies of the global geomagnetic field from a region with little data. The study will support the training of undergraduate and graduate students and the results will be widely communicated to the general public through Web sites, public lectures and K-12 teaching initiatives.

该奖项由《2009 年美国复苏与再投资法案》（公法 111-5）资助。该奖项将支持北极全新世古地磁记录的重建，并调查与区域气候的联系。该项目的重点是从阿拉斯加西北和东北部以及加拿大麦肯齐三角洲、班克斯岛和维多利亚岛的湖泊中回收连续的 3 至 5 m 长的沉积物岩心。四个地点各两个相似湖泊系统的多个岩心将被回收。这些岩心将成为一系列分析技术的对象，包括磁性、岩石地层学、地球化学和生物测量。选定的研究地点将提供追溯到全新世 20ka 的记录，提供迄今为止最长的高分辨率北极古地磁记录。年表将主要通过使用现代 AMS C-14 技术的放射性碳测年得出。将使用一系列方法来记录该地区的气候历史，包括环境磁学、地球化学、扫描 XRF、生物二氧化硅以及与加拿大合作者合作的一系列生物气候代理。将通过对 u 通道样本进行交替场消磁，对每个湖的多个岩心进行古地磁和环境磁记录的研究。这项研究的“智力价值”在于开发了一套新的全新世古地磁观测结果，该观测结果将在空间和时间上确认和扩展之前的北极古地磁观测结果，并补充正在进行的北极和全球全新世古地磁观测结果。 倡议。扩展的北极古地磁记录将允许与冰岛的海洋记录以及目前在阿拉斯加湾、北冰洋和巴芬湾开发的海洋记录进行直接比较。这些新记录将允许重建北极全新世（甚至可能更远）的古地磁记录，为测试地磁假说提供必要的约束，有助于北极磁地层网络的持续发展，以促进海洋和陆地古记录的测年，并为地磁场是否在气候系统中发挥作用提供新的约束。 该研究的影响与科学和教育成果有关。该研究产生的数据与第一阶段和其他已发表研究的结果相结合，将提供北极周围180°的古地磁视角，记录过去的变化，并为北磁极持续运动的未来行为和影响提供古约束。这些数据还将有助于区分地磁控制与太阳控制对陆地宇宙射线通量和宇宙同位素产生的贡献，对电信、人类健康、全球生态系统和气候具有实际影响。数据将贡献给 magIC、sedDB 和 NOAA 古气候数据库，并用于补充正在进行的来自数据很少的地区的全球地磁场球谐研究。该研究将支持本科生和研究生的培训，研究结果将通过网站、公开讲座和 K-12 教学计划向公众广泛传播。