Collaborative Research: Systematic Comparisons of Regular and Slow Earthquakes in Central and Southern California

合作研究：加州中部和南部定期地震和慢震的系统比较

• 批准号: 1736197
• 负责人: Zhigang Peng
• 金额: $ 16.1万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1736197&HistoricalAwards=false
• 关键词: Collaborative; Research; Systematic; Comparisons; Regular

Nontechnical This project aims to understand different behaviors of regular and slow earthquakes in Central and Southern California. The recent discovery of slow earthquakes broadens our view on how active faults relieve tectonic stresses. By applying various techniques to extensive seismic data collected by EarthScope and other permanent networks, the Principal Investigators (PIs) are creating better images of detailed fault zone structures within and below the depth where regular earthquakes occur. The PIs also hope to better understand how fault zone properties control different fault slip behaviors (regular vs slow). The project will improve our estimation of when and where large earthquakes occur and help to evaluate future seismic hazards. Because slow deformation may occur before large earthquakes, better tracking slow earthquakes could also help to better understand the processes relevant to how earthquakes initiate and interact. The PIs are developing new tutorials on triggering and detection of regular and slow earthquakes from seismic data. In addition, they are developing products to visualize and hear seismic data relevant this project. All these activities help to attract next generation scientists into the seismological field, and train them with state-of-the-art tools so that they can succeed in their future careers. This project also supports training of two graduate students and an international collaboration with Japanese researchers.Technical The newly discovered deep tectonic tremor and accompanying slow-slip events have changed our view on how accumulated tectonic stresses are released through fault movement below the seismogenic zone. Deep tremor has been clearly observed along the Parkfield-Cholame section of the San Andreas Fault (SAF) in Central California since around the time when the Earthscope project started more than 15 years ago. However, except a few cases, tremor has not been ubiquitously found along the San Jacinto Fault (SJF) and other major faults in Southern California. Although progress has been made to further understand the physical mechanisms for tremor and regular earthquakes, many fundamental questions remain open. These include: 1. What are the primary factors that control different tremor and microearthquake behaviors in Central and Southern California? 2. How do tremor and low-frequency earthquakes (LFEs) differ from regular earthquakes? 3. What are in situ fault zone properties at depth where regular and slow earthquakes occur? To answer these questions, the PIs are conducting a systematic analysis of regular and slow earthquakes in Central and Southern California using state-of-the-art techniques and available dataset in these regions. Specifically, the PIs are performing the following research tasks: 1. Detect and relocate microearthquakes along the Parkfield section of the SAF and along the SJF in Southern California; 2. Better detect and locate tremor and LFEs along the SJF in Southern California and compare their behaviors with those in Central California; 3. Quantify the triggerability of microearthquakes and tremor/LFEs in these regions; and 4. Delineate internal fault zone structures using Vp/Vs ratios and other imaging methods.The project goal is to obtain highly accurate locations of microearthquakes and LFEs in both regions, and use them to study their responses to external stress perturbations, and obtain in situ fault zone properties that control different behaviors of regular and slow earthquakes in Central and Southern California. In addition, the PIs are continuing their development of online tutorials on earthquake triggering and detection, and visualization and sonification products related to Earthscope. These activities help to educate general audience with frontier earthquake science, attract next generation scientists into the seismological field, and train them with state-of-the-art tools so that they can succeed in their future careers. This project also supports training of two graduate students and an international collaboration with Japanese researchers.

非技术性这个项目旨在了解中部和南加州的常规和缓慢地震的不同行为。最近发现，缓慢地震的发现扩大了我们对主动断层如何缓解构造应力的看法。通过将各种技术应用于Earthscope和其他永久网络收集的广泛的地震数据，主要研究人员（PIS）正在为发生常规地震的深度内外创建更好的详细断层区域结构图像。 PI还希望更好地了解断层区特性如何控制不同的断层滑动行为（常规与慢速）。该项目将改善我们对大地震发生何时何地的估计，并有助于评估未来的地震危害。因为在大地震发生之前可能会发生缓慢的变形，所以更好地跟踪慢速地震也可能有助于更好地理解与地震的发起和相互作用相关的过程。 PI正在开发有关从地震数据触发和检测常规和缓慢地震的新教程。此外，他们正在开发可视化和听取地震数据的产品。所有这些活动有助于吸引下一代科学家进入地震学领域，并使用最先进的工具训练他们，以便他们可以在未来的职业中取得成功。该项目还支持对两名研究生的培训，并与日本研究人员进行国际合作。技术新发现的深层构造震颤和随附的慢滑态事件改变了我们对通过地震质区下方的断层运动如何释放积累的构造压力的看法。自从15年前开始的EarthScope项目开始时，就已经在加利福尼亚州中部的San Andreas断层（SAF）的Parkfield色但是，除少数案件外，在圣哈辛托断层（SJF）和南加州的其他主要断层及其其他重大断层时，震颤尚未被普遍存在。尽管取得了进展，以进一步了解震颤和常规地震的物理机制，但许多基本问题仍然开放。其中包括：1。控制着加州中部和南部的不同震颤和微观行为的主要因素是什么？ 2。震颤和低频地震（LFE）与常规地震有何不同？ 3。在发生常规和缓慢地震的深度处有什么原位断层区的特性？为了回答这些问题，PIS正在使用最先进的技术和这些地区的可用数据集对中部和南加州的常规和缓慢地震进行系统分析。具体来说，PI正在执行以下研究任务：1。检测和重新定位SAF的Parkfield部分以及南加州的SJF沿线； 2。更好地检测并找到南加州的SJF沿SJF的震颤和LFE，并将其行为与加利福尼亚中部的行为进行比较； 3。量化这些区域中微夸克和震颤/LFE的触发性；和4。使用VP/VS比率和其他成像方法来描述内部断层区结构。项目目标是在两个区域中获得高度准确的微夸克和LFE的位置，并利用它们来研究其对外部压力扰动的响应，并获得处境断层的特性，以控制常规和慢速地震的中部和南部Califor Califor california的不同行为。此外，PIS继续开发有关地震触发和检测的在线教程，以及与Earthscope相关的可视化和超索产品。这些活动有助于通过边境地震科学教育普通观众，吸引下一代科学家进入地震学领域，并使用最先进的工具训练他们，以便他们可以在未来的职业中取得成功。该项目还支持对两名研究生的培训以及与日本研究人员进行的国际合作。