Imaging the deep root of the San Andreas Fault zone at Parkfield, CA, with magnetotelluric measurements

通过大地电磁测量对加利福尼亚州帕克菲尔德圣安德烈亚斯断层带的深根进行成像

• 批准号: 5423681
• 负责人: Professor Dr. Oliver Ritter
• 金额: --
• 依托单位: Sektion 2.2: Geophysikalische Abbildung des Untergrunds
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2004
• 资助国家: 德国
• 起止时间: 2003-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5423681?language=en
• 关键词: Imaging; deep; root; San; Andreas

Magnetotelluric (MT) studies have always played an important role in the investigation of the San Andreas Fault. Due to short profile lengths, they have generally focused on the geometry and nature of the upper crustal fault. Geophysical imaging of the ductile roots is essential, however, to address the dynamics of interplate transform faulting. We propose a high resolution MT survey in the vicinity of the SAFOD site near Parkfield, California following a 50 km reflection/refraction seismic profile [Hole and Ryberg, 2003]. New and existing MT data sets [Unsworth et al., 2000; Park et al., 1991] will be modeled jointly using 2D inversion procedures. Acquisition of additional spatially distributed sites will help separate off-profile features from structure at depth. Accompanying 2D anisotropic and 3D forward modeling studies will be carried out to examine more complicated conductivity structures. Acquiring seismic and magnetotelluric data along a coincident profile is an unprecedented opportunity to utilize the combined imaging power of the two methods. The project will be coordinated and carried out in close cooperation with scientists and partner institutions in the United States.

大地电磁（MT）研究一直在圣安德烈亚斯断层的调查中发挥着重要作用。由于剖面长度较短，他们通常侧重于上地壳断层的几何形状和性质。地球物理成像的韧性根是必不可少的，但是，解决板间转换断层的动力学。我们建议在加州帕克菲尔德附近的SAFOD场地附近进行高分辨率MT勘探，并遵循50 km反射/折射地震剖面[Hole和Ryberg，2003]。新的和现有的MT数据集[Unsworth等人，2000; Park等人，1991]将使用2D反演程序联合建模。获取更多的空间分布地点将有助于将剖面外特征与深度结构分开。将进行伴随的二维各向异性和三维正演模拟研究，以检查更复杂的导电性结构。沿沿着重合剖面采集地震和大地电磁数据是利用这两种方法的组合成像能力的前所未有的机会。该项目将与美国的科学家和伙伴机构密切合作进行协调和实施。