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

21 年 InSAR、GPS 和重复地震的圣安德烈亚斯断层中央蠕变段随时间蠕变模型

• 批准号: 1357079
• 负责人: Manoochehr Shirzaei
• 金额: $ 26.23万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-01 至 2018-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1357079&HistoricalAwards=false
• 关键词: Time; dependent; Creep; Model; Central

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.

拟议的工作将涉及对圣安德烈亚斯中央蠕动部分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，将使用C波段、L波段和X波段合成孔径雷达数据生成三个时间序列的地表变形，时间跨度为1992-2013年。合成孔径雷达图像是由地球资源卫星1、2号、环境卫星和ALOS以及Cosmo-SkyMed卫星获取的，将通过一个与时间有关的逆建模方案，利用密集的全球定位系统数据网络和重复地震目录对这些图像进行联合探索。这种模拟方案可以解决在地壳上部的滑动的4维分布。它也使我们能够进行系统和详细的研究的空间和时间的关联的地震滑动脉冲和事件。该项目，特别是，侧重于探索地震和地震变形过程之间的相互作用的性质，发生在断层带和特征的蠕动脉冲沿着中央圣安德烈亚斯断层（CSAF）的运动学模型。特征性的重复地震将提供地球瞬时活动的独特信息？的外壳。断层滑动与断裂带岩石和邻近地壳块体的力学性质有关，所提出的活动性也可以评价地壳性质的一级变化。瞬变滑动随时间变化的运动学模型也将允许调查长期和短期瞬变行为之间的可能关系，更好地了解断层带的时空变化的变形场，以大深度是至关重要的，了解活动构造，断层-断层相互作用和大地震的发生。为此，从这个NSF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集群的作用。我们预计，长期的社会效益，从提高认识的地震滑动瞬变，它们与区域应变异常的关系，并改进模型的地震周期，应改善地震预报和中长期预测。该项目还将为一名早期职业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。从这个研究项目中获得的问题和结果将被纳入本科和研究生教学。