Collaborative Research: A Deep-AUV Magnetic and Seismic Study of the Hawaiian Jurassic Crust - The Global Significance of Jurassic Magnetic Anomalies

合作研究：夏威夷侏罗纪地壳深部 AUV 磁和地震研究 - 侏罗纪磁异常的全球意义

• 批准号: 1029573
• 负责人: William Sager
• 金额: $ 10.33万
• 依托单位: Texas A&M Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1029573&HistoricalAwards=false
• 关键词: Collaborative; Research; Deep; AUV; Magnetic

Funds are provided for a two-year study, initially involving a 42-day cruise to collect two high-resolution seismic profiles and near-bottom magnetic field data from the Hawaiian Lineation Jurassic Magnetic Quiet Zone (JMQZ) using an AUV. The PIs plan to obtain 800 km long magnetic profiles as well as local seismic reflection and refraction data using a portable multichannel seismic system and sonobuoys. Seismic data will allow them to evaluate whether the Jurassic crust has been affected by later intra-plate Cretaceous volcanism. This magnetic data will be compared to the previously studied JMQZ data from the Japanese Lineation. The latter reveals rapid reversal and decreasing field intensity as well as a period of apparently incoherent anomalies with short wave lengths and low amplitudes. If real and global (as opposed to a local bad signal) this low amplitude zone represents an very unusual field behavior in Earth?s magnetic field history. The new data from Hawaii and its comparison with Japanese results will allow testing the hypothesis that this unusual field behavior was indeed global, which has important implications for dynamics of the deep Earth and for the construction of a robust geomagnetic polarity time scale for the Mid-Jurassic period.Broader impacts include discovery while promoting teaching and training at sea for graduate and undergraduate students. Public outreach is also planned through internet and WHOI exhibits. The scientific results could have far reaching implications for Earth dynamics, magnetic field behavior and geomagnetic polarity time scale and useful to other workers in the field.

为为期两年的研究提供资金，最初包括为期42天的巡航，使用AUV从夏威夷线性侏罗纪磁静区（JMQZ）收集两条高分辨率地震剖面和近底磁场数据。研究所计划利用便携式多通道地震系统和声纳浮标获取800公里长的磁剖面以及当地地震反射和折射数据。地震数据将使他们能够评估侏罗纪地壳是否受到后期板内白垩纪火山活动的影响。这一磁测数据将与先前研究的日本线理JMQZ数据进行比较。后者揭示了快速反转和降低的场强以及一段明显的非相干异常，波长短，振幅低。如果真实的和全球（而不是一个局部的坏信号），这个低振幅区代表了一个非常不寻常的领域在地球上的行为？的磁场历史。来自夏威夷的新数据及其与日本结果的比较将允许检验这种不寻常的场行为确实是全球性的假设，这对地球深处的动力学和建立强有力的地磁极性具有重要影响侏罗纪中期的时间尺度。更广泛的影响包括发现，同时促进研究生和本科生的海上教学和培训。还计划通过互联网和世界卫生组织展览向公众宣传。科学结果可能对地球动力学，磁场行为和地磁极性时间尺度产生深远的影响，并对该领域的其他工作者有用。