Utah FORGE: Phase 3 Magnetotelluric (MT) Data

New high-quality tensor MT data at 122 sites, including the vertical magnetic field and utilizing ultra-remote referencing, have been acquired over the Utah FORGE project area. The results will be used to delineate the densities of faults and fractures in crystalline basement rocks, to define the heat sources, and to derive baseline 3D resistivity structure for later MT monitoring of temporal changes in resistivity structure following well stimulation in the EGS reservoir.

There are three files here related to Utah FORGE magnetotelluric (MT) data acquisition and processing. The FORGE MT EDIs zip file contains the observed MT responses in industry-standard EDI format. For each site, there is an EDI response file that utilized a local independent reference for noise cancellation, and a file that utilized a distant reference cancelling noise associated with the DC transmission line of the Delta IPP passing down the west side of Milford Valley. These two site files could be merged as appropriate.

The FORGE Model Cell Center file contains the model volume of the 3D Forge MT inversion for characterizing the resistivity structure in the project area. It was derived using finite element inversion methodology described in Wannamaker et al, in the attached FORGE Phase3 Geophysics paper, from the MT observation EDI files. It is ASCII format (.dat) and entries are defined at top of the file in a simple x-y-z-Rho listing in UTM coordinates. The element layers drape the topography so the Rho value layers are not purely horizontal slices. This greatly simplifies the listing.

在犹他FORGE项目区域内，通过122个站点收集了高质量的张量MT数据，包括垂直磁场，并采用了超远程参考技术。这些数据结果将用于描绘结晶基底岩石中的断层和裂缝密度，界定热源，并推导出后续MT监测中，在EGS储层井刺激后电阻率结构变化的基线3D电阻率结构。在此，提供了与犹他FORGE磁大地测量（MT）数据采集和处理相关的三个文件。FORGE MT EDI文件压缩包包含行业标准的EDI格式中观测到的MT响应。对于每个站点，都有一个利用本地独立参考进行噪声消除的EDI响应文件，以及一个利用远程参考消除与米福德山谷西侧Delta IPP直流输电线路相关的噪声的文件。这两个站点文件可以根据需要合并。FORGE模型单元格中心文件包含用于表征项目区域内电阻率结构的3D Forge MT反演模型体积。该模型是通过有限元反演方法得到的，该方法在附带的FORGE Phase3地球物理学论文中由Wannamaker等人描述，并基于MT观测EDI文件。该文件为ASCII格式（.dat），条目在文件顶部定义，采用简单的x-y-z-Rho列表，以UTM坐标表示。元素层覆盖地形，因此Rho值层并非纯粹的水平切片。这极大地简化了列表。