Collaborative Research: A National Instrument Facility for ElectroMagnetic Studies of the Continents

该奖项为加利福尼亚大学河滨分校购买便携式磁力计和相关现场设备提供了部分支持，这些设备将成为中央管理设备池的一部分，并可供美国研究人员在使用大地电磁（MT）技术成像地球深层内部结构的项目中进行现场部署。加州大学河滨分校承诺提供购买设备系统所需的剩余资金。最近，利用大地电磁法对地壳和上地幔进行遥感，在产生具有良好空间分辨率的内部结构图像和与地震图像（地震速度）不同的内容（电导率）方面取得了重大进展。大地电磁法利用地球外部地磁场变化在地球内部产生的随时间变化的自然电磁场。感应电流（大地电流）扩散到地球，并从电阻率结构的非均匀性中散射回来。地表水平磁场和电场之间复杂的、频率相关的关系被称为大地电磁学阻抗，可以通过倒置来求解内部的电阻率（或导电性）结构。内部的电导率特性引起了相当大的兴趣，因为它们在很大程度上取决于导电离子流体或熔体的存在，而这些离子流体或熔体很难或不可能用其他遥感技术检测到。＊＊＊

9616986 Park This award provides partial support for the acquisition of portable magnetometers and associated field equipment by the University of California at riverside that will become part of a centrally managed pool of equipment and made available to US researchers for field deployment in projects using the magnetotelluric (MT) technique to image the Earth's deep interior structure. The University of California at Riverside is committed to providing the remaining funds necessary to acquire the equipment system. Remote sensing of the Earth's crust and upper mantle using MT methods recently has made significant progress in producing images of internal structures with good spatial resolution and with content (electrical conductivity) that is distinct from seismic images (seismic velocities). The MT method makes use of the time-dependent natural electromagnetic fields (EM) induced inside the Earth by the variations of the Earth's external geomagnetic field. The induced electric (telluric) currents diffuse into the Earth and are scattered back from heterogeneities in the electrical resistivity structure. The complex, frequency dependent, relationship between the horizontal magnetic and electric fields at the surface is called the MT impedance and can be inverted to solve for the resistivity (or conductivity) structure of the interior. Conductivity properties of the interior are of considerable interest because they depend strongly on the presence of conducting ionic fluids or melts which are difficult or impossible to detect with other remote sensing techniques. ***