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

该项目为两年的研究提供了资金，最初包括42天的巡航，使用AUV从夏威夷线纹侏罗纪磁静带（JMQZ）收集两个高分辨率地震剖面和近底部磁场数据。pi计划使用便携式多通道地震系统和声纳浮标获得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来的白垩纪板块内火山活动的影响。这些磁性数据将与先前研究的日本线理JMQZ数据进行比较。后者显示出快速反转和场强减弱，以及一段明显的短波低振幅非相干异常。如果是真实的和全球性的（而不是局部的坏信号），这个低振幅区代表了地球上一个非常不寻常的磁场行为。S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测试这种不寻常的磁场行为确实是全球性的假设，这对地球深部动力学和中侏罗纪时期强大的地磁极性时间尺度的构建具有重要意义。更广泛的影响包括发现，同时促进研究生和本科生在海上的教学和培训。还计划通过互联网和WHOI展览进行公众宣传。这些科学成果对地球动力学、磁场行为和地磁极性时间尺度具有深远的意义，对其他领域的工作人员也有借鉴意义。

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.