Time-dependent Creep Model of the Central Creeping Section of the San Andreas Fault From 21 Years of InSAR, GPS and Repeating Earthquakes

拟议的工作将解决圣安地列斯中央爬行段的空间大地测量和地震数据的高级分析，全面整合和仔细解释。为此，将利用c波段、l波段和x波段SAR数据，生成1992-2013年的三个地表变形时间序列。SAR图像由ERS1、2、Envisat、ALOS和cosmos - skymed卫星获取，这些卫星将通过时间相关的逆建模方案，与密集的GPS数据网络和重复地震目录共同探索。这种建模方案可以解决上地壳中滑移的四维分布。它还使我们能够对地震滑动脉冲和地震事件的时空联系进行系统和详细的研究。该项目特别侧重于探索断裂带中地震和地震变形过程之间相互作用的本质，并描述沿中央圣安德烈亚斯断层（CSAF）的蠕变脉冲的运动学模型。有特征的重复地震将提供地球瞬态活动的独特信息。地壳。断层滑动与断裂带岩石和相邻地壳块体的力学性质有关，所提出的活动也可以评价地壳性质的一级变化。瞬态滑移的时间相关运动学模型也将允许研究长期和短期瞬态行为之间的可能关系。提高对大深度断裂带时空变化变形场的认识，对于理解活动构造、断层-断层相互作用和大地震的发生至关重要。为此，这个由美国国家科学基金会资助的项目的结果将使我们能够评估地震断层滑动瞬变在地震发生和聚集中的作用。我们期望通过提高对地震滑动瞬变的理解、它们与区域应变异常的关系以及改进的地震周期模型来改善地震预报和中长期预测，从而获得长期的社会效益。该项目还将为一名早期科学家提供部分支持，并为两名计划直接参与该项目的研究生提供宝贵的研究经验。本研究项目所涉及的问题和结果将纳入本科和研究生的教学。

The proposed work will address the advanced analysis, full integration, and careful interpretation of space-geodetic and seismic data over the central creeping section of the San Andreas. To this end, three time series of the surface deformation, using C-Band, L-Band and X-band SAR data and spanning period 1992-2013, will be generated. The SAR images are acquired by ERS1, 2, Envisat and ALOS and Cosmo-SkyMed satellites, which will be jointly explored with a dense network of GPS data and catalogue of repeating earthquakes, through a time-dependent inverse modeling scheme. This modeling scheme allows resolving the 4-dimensional distribution of slip in the upper crust. It also enables us to conduct a systematic and detailed study of the spatial and temporal association of the aseismic slip pulses and events. This project, in particular, is focused on exploring the nature of interactions between seismic and aseismic deformation processes that occur in the fault zone and characterizing the kinematic models of creep pulses along the Central San Andreas Fault (CSAF). Characteristic repeating earthquakes will provide unique information on transient activity in the Earth?s crust. Fault slip is tied to the mechanical properties of the fault zone rocks and adjoining crustal blocks and the proposed activity can also evaluate the first order changes of crustal properties. The time-dependent kinematic model of transient slip will also allow investigating the possible relationships between long-term, and short-term transient behavior.An improved understanding of the spatially and temporally varying deformation field of fault zones to great depth is critically important for understanding active tectonics, fault-fault interaction and the occurrence of large earthquakes. To this end the results from this NSF funded project will allow us to assess the role of aseismic fault slip transients in earthquake occurrence and clustering. We anticipate long-term societal benefits from improved understanding of aseismic slip transients, their relation to regional strain anomalies, and improved models of the earthquake cycle that should improve earthquake forecasts and intermediate to longer-term predictions. This project will also provide partial support for an early-career scientist as well as valuable research experience for two graduate students who are planned to directly involve in this project. The issues and results obtained from this research project will be incorporated in undergraduate and graduate teachings.