Surface wave triggering of earthquakes and non-volcanic tremor: Insights into the physics of rupture

地震和非火山颤动的表面波触发：对破裂物理学的见解

• 批准号: 0944257
• 负责人: Aaron Velasco
• 金额: $ 24.97万
• 依托单位: University of Texas at El Paso
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0944257&HistoricalAwards=false
• 关键词: Surface; wave; triggering; earthquakes; non

This proposal outlines detailed analyses and modeling of surface waves in relation to triggering of both earthquakes and non-volcanic tremor. In particular, we have two main hypotheses that we will test: 1) the orientation of the local stress field and the orientation of the transient stresses induced by the surface waves combine to generate failure and 2) triggered earthquakes and triggered non-volcanic tremor exhibit similar failure mechanisms caused by transient stress fluctuations. We will test these two hypotheses by analyzing numerous large (M 7.0) earthquakes in regions with good local/regional network coverage, local/regional catalogs, and with documented triggered earthquakes and NVT. We will also develop a simple failure model that can explain our observations of triggered earthquakes and NVT. Our results will provide fundamental insight into stresses that trigger events, and whether these two seemingly different processes are indeed similar. Closely studying surface waves and triggering holds the key for understanding the physics of rupture.A growing body of scientific studies has demonstrated that the passage of transient signals, or seismic waves, from large earthquakes can remotely trigger small earthquakes and non-volcanic tremor thousands of kilometers from an epicenter of a large earthquake. These two phenomena, at first glance, appear quite different, with the only common attribute being the triggering stress: surface waves. Triggered non-volcanic tremor (NVT) is the radiation of non-impulsive seismic energy not associated with volcanic processes that occurs coincidentally with the passage of the surface waves of a larger earthquake; similarly, dynamically triggered earthquakes are generally small earthquakes that trigger coincidentally or shortly after the arrival of surface waves from a larger earthquake. Given the fact that these two triggered phenomena occur on a frequent basis, a detailed investigation into both the local and triggering, transient stress fields could provide fundamental insight into the physical mechanisms of rupture failureThis project will gain fundamental insight into dynamically triggered earthquakes and non-volcanic tremor, one of the most intriguing discoveries in earthquake science that has occurred in the past 8 years. Results of the project will be published in peer-reviewed journals and presented at national conferences to share with the scientific community. Furthermore, the University of Texas at El Paso is a Hispanic Serving Institute (HSI) and we will actively recruit undergraduate and graduate students, plus a postdoctoral scholar from underrepresented groups to participate in this project.

该建议概述了与触发地震和非volcanic震颤有关的详细分析和表面波的建模。 特别是，我们有两个主要的假设，我们将测试：1）局部应力场的取向以及表面波诱导的瞬态应力的取向，结合了失败，2）触发地震并触发了非沃尔卡尼克震颤，表现出了瞬态应力波动引起的类似的失败机制。我们将通过分析具有良好局部/区域网络覆盖范围，本地/区域目录的地区的许多大型（M 7.0）地震来检验这两个假设，并进行了记录的触发地震和NVT。 我们还将开发一个简单的失败模型，可以解释我们对触发地震和NVT的观察结果。我们的结果将为触发事件的压力以及这两个看似不同的过程是否确实相似，为压力提供基本的见解。 仔细研究表面波和触发是理解破裂物理的关键。越来越多的科学研究体表明，从大地震发生的瞬态信号或地震波的通过可以远程触发小地震和非volcanic震颤，而非volcanic震颤的震颤数千公里远离大地震景点。乍一看，这两个现象似乎完全不同，唯一常见的属性是触发压力：表面波。 触发的非volcolic震颤（NVT）是与火山过程无关的非冲动地震能量的辐射，而火山过程与较大地震的表面波的通过偶然发生。同样，动态触发的地震通常是小地震，在从较大的地震中出现表面波后偶然或不久触发。 鉴于这两个触发的现象经常发生的事实，对局部和触发的瞬态压力场的详细研究可能会提供对破裂的物理机制的基本见解，这将获得对动态触发地震的动态洞察力的基本洞察力，以及在地球上发生的，这是一个发生在地球上的巨大触发者，这是一个发生在地球上的一项探索的事物。 该项目的结果将在同行评审期刊上发表，并在国家会议上与科学界分享。此外，德克萨斯大学埃尔帕索分校是西班牙裔服务学院（HSI），我们将积极招募本科生和研究生，以及来自代表性不足的团体的博士后学者参加该项目。