Seismic Indicators of Time-Varying Deep Deformation along the Central San Andreas Fault

[0544730]中部圣安德烈亚斯断层深部时变变形的地震指标了解板块边界断裂带的深部时变变形场对于认识活动构造、断层-断层相互作用和大地震的发生具有重要意义。然而，由于大地测量的范围、覆盖范围和采样频率有限，以及从地表运动测量推断垂直断层上的深度变形所需的基本权衡和假设，沿着垂直走滑板块边界（如圣安德烈亚斯断层）进行大规模时变深度变形的测量一直很难获得。为了更清楚地了解加州中部圣安德烈斯断层（SAF）板块边界深部瞬态变形的作用，我们分析了深断裂带变形的新地震指标数据，并将其与变形和中到大地震发生的大地测量数据进行了比较。新的地震指标有两种类型：1)特征重复微地震（用于推断深断层地震滑动信息）和2)深部非火山震颤活动（深部次发震岩石圈幕式慢滑事件的指标）。这个项目将产生一个大范围的地震活动目录，该目录目前还不存在，可能会用于相关研究。建议的活动也将包括研究生博士论文的一个组成部分，并将是本科生毕业论文的主要组成部分。结果将通过K-12之旅和伯克利地震实验室的年度公众开放日向公众传播，并在科学界的会议和出版物中向科学界传播。结果也将被纳入加州地震的高年级本科课程（eps 130）。两名本科生也通过独立研究课程（eps 199）参与了初步和正在进行的研究。项目活动将通过公众教育、学生的教育和培训，以及提供关于沿SAF板块边界发生的复杂过程的信息和该地区滑差积累的时变方面的信息，使社会受益，所有这些都是准确评估该地区活动构造造成的地震危险的关键输入。

0544730NadeauSeismic Indicators of Time-Varying Deep Deformation along the Central San Andreas FaultUnderstanding the time-varying deformation field of plate bounding fault zones at great depthis important for understanding active tectonics, fault-fault interactions and the occurrence oflarge earthquakes. However, measurements of large-scale time-varying deep deformation alongvertical strike-slip plate boundaries such as the San Andreas Fault have been difficult to obtain,due to the limited extent, coverage and sampling frequency of geodetic measurements and thefundamental trade-offs and assumptions required to infer deep deformation on vertical faults from measurements of surface motion.To more clearly understand the role of deep transient deformation along the San AndreasFault (SAF) plate boundary in central California, data from new seismic indicators of deep faultzone deformation are analyzed and compared to geodetic measurements of deformation andmoderate to large earthquake occurrence. The new seismic indicators are of two types: 1)characteristically repeating microearthquakes (used to inferred deep-fault aseismic slipinformation) and 2) deep non-volcanic tremor activity (indicators of episodic slow-slip events inthe deep sub-seismogenic lithosphere).This project will produce a large-scale catalog of tremor activity along 175km of the central SAF that does not currently exist and that will likely be of use for relatedresearch. The proposed activity will also comprise a component of a graduate student's Ph.D.dissertation and will be a major component of an undergraduates senior thesis. Results will bedisseminated to the public through K-12 tours and annual public open houses of the BerkeleySeismological Lab and to the scientific community scientific community at meetings and inpublication . Results will also be incorporated into an upper-division undergraduate course onCalifornia Earthquakes (eps 130). Two undergraduates are also participating in the preliminaryand ongoing research through an independent research course (eps 199). Project activities willbenefit society through public education, education and training of students and by providinginformation on the complex processes occurring along the SAF plate boundary and the timevaryingaspects of slip-deficit accumulation in the region, all of which are critical inputs for theaccurate assessment of the seismic hazard posed by the active tectonics of this region.