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

中央圣安德烈亚斯断层沿线时变深层变形的地震指标

• 批准号: 0544730
• 负责人: Robert Nadeau
• 金额: $ 5.55万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0544730&HistoricalAwards=false
• 关键词: Seismic; Indicators; Time; Varying; Deep

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.

圣安德烈亚斯断层中部深部时变形变的地震标志深入了解板块边界断裂带的时变形变场，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，以及根据地表运动测量推断垂直断层上的深部变形所需的基本权衡和假设，一直难以获得圣安德烈亚斯断层等垂直走滑板块边界的大规模时变深部形变的测量结果。为了更清楚地了解加州中部圣安德烈斯断层(SAF)板块边界的深部瞬时形变的作用，分析了来自新的断裂带深部形变指标的数据，并将其与形变和中到大地震发生的大地测量结果进行了比较。新的地震指示器有两种类型：1)特征重复的微震(用于推断深部断层的非地震滑动信息)和2)深部非火山地震活动(深部次地震岩石圈幕式慢滑事件的指示器)。该项目将产生目前尚不存在的沿中央SAF 175公里的大规模地震活动目录，这可能将用于相关研究。拟议的活动还将包括研究生博士论文的一个组成部分，并将是本科生高级论文的一个主要组成部分。结果将通过K-12巡回演出和伯克勒地震实验室的年度公众开放日向公众传播，并在会议和出版物上向科学界科学界传播。研究结果也将被纳入加州地震的高级本科课程(EPS 130)。两名本科生还通过独立研究课程(EPS 199)参与了初步研究和持续研究。项目活动将通过对学生进行公共教育、教育和培训，并提供关于苏丹武装部队板块边界沿线发生的复杂过程以及该区域滑动赤字累积的不同方面的信息，从而造福社会，所有这些都是准确评估该区域活动构造造成的地震危险的关键投入。