Study of the Internal Structure, Dynamic Rupture, and Post-Earthquake Healing of the Hector Mine Earthquake Rupture Zone Using Fault-Zone Trapped Waves

1999年加州赫克托矿M7.1级地震为断层带导波的捕获提供了一个很好的场地。 在美国地质勘探局协调的主震发生3天后，我们在震中附近的地表破裂处部署了一个由60通道GEOMETRICS记录仪组成的PASSCAL地震阵列，并在10天内记录了约800次余震。 数据显示，4-6 Hz的断层带捕获波在车站接近地面破裂的事件发生在破裂带内。 随后，SCEC在破裂区的两个地点组织了83个PASSCAL REFTEK的部署。在4周内记录了约2000次余震。 我们建议对断裂带捕获波数据进行系统分析和FD-FE建模，以获得更多有关破裂带内部结构、断层分段的物理本质、断裂带结构与动态破裂过程之间的关系以及断裂愈合的信息。大地震后的断层。 本方案的主要任务是：1.对断裂带的物理性质和精细结构进行了三维描述。 2.利用爆炸重复地震勘测，以监测断层愈合。 3.模拟以陷波为特征的断层阶跃破裂过程，评估破裂过程中破裂速度的变化、滑移程度、动应力和非线性能量耗散，以更好地理解破坏机制、断层摩擦和流变。 4.分析剪切波分裂，以获得关于破裂区周围应力状态和断裂基质的更多信息。

EAR-0001132University of Southern CaliforniaThe M7.1 Hector Mine, California, earthquake in 1999 provides an excellent site for capture of fault-zone guided waves. 3 days after the mainshock coordinated by the USGS, we deployed a seismic array of a 60-channel GEOMETRICS recorder from PASSCAL across the surface rupture near the epicenter and recorded ~800 aftershocks in 10 days. The data show 4-6 Hz fault-zone trapped waves at stations close to the surface rupture for events occurring within the rupture zone. Afterwards, the SCEC organized a deployment of 83 PASSCAL REFTEKs at 2 sites on the rupture zones. ~2000 aftershocks were recorded in 4 weeks. We propose to do a systematic analysis and FD-FE modeling of fault-zone trapped wave data for more information about the internal structure of the rupture zone, physical nature of fault segmentation, the relationship between the fault zone structure and dynamic rupture process as well as the healing of the fault after a major earthquake. The main tasks of this proposal are: 1. To delineate the physical properties and fine structure of the fault zone in 3-D. 2. to repeat seismic surveys using explosions for monitoring the fault healing. 3. to simulate the rupture through the fault stepovers characterized by trapped waves, and assess the rupture velocity variations, extent of slip, dynamics stresses and nonlinear energy dissipation in the fault zone during the rupture for a better understanding the damage mechanism, fault friction and rheology. 4. to analyse shear-wave splitting for additional information on the stress state and fracture matrix around the rupture zone.