Collaborative Research: Understanding Fault Zone Compliance by Seismic Probing of InSAR Anomalies

这个项目的目的是测量断裂带中的岩石比周围未破裂的岩石弱多少。该机构联盟将部署地震仪来记录爆炸和地震。实验将首先根据P、S和面波速度来破译地壳的结构，然后根据岩石强度和裂缝密度来解释波速图。该小组还将使用GPS测量几年内的地面变形。这些结构将与卫星变形监测中注意到的特征进行比较。收集到的见解将有助于理解断层系统为什么会形成这样的情况。更具体地说，加州断层系统中断层的间距和地震频率已经成熟，需要更深入的了解，这个项目将努力在这个方向上取得进展。调查人员建议整合加州大学洛杉矶分校、加州大学圣地亚哥分校和南加州大学的专业知识，系统地绘制Calico和Pinto山断裂带的结构横截面，横跨表现出异常应变的剖面，以响应兰德斯和赫克托矿震。他们将在主动震源实验和被动震源实验中部署便携式地震仪，以绘制浅层断层结构图和成像深层结构。他们的观测将检验和扩展先前的InSAR建模，以更好地解决断裂带异常的幅度、宽度和深度。该项目将使用多种方法探索莫哈韦发震断层的结构和演化。这一结果将限制断层带的大小、薄弱程度和地震周期内强度的变化，并有助于更好地理解断层机制。该项目支持三所大学的教育项目，包括研究生研究和本科生的实地考察项目。各机构之间的合作将通过私人投资机构、学生和博士后的定期会议来促进，讨论相关的科学和项目的状况。这项研究的结果将通过出版物、会议介绍和媒体联系，包括一个项目网站，广泛传播。这项研究将提供对断层行为的更好理解，最终导致改进地震预报，减少人员伤亡和损失。

This project aims to measure how much weaker are the rocks in fault zones than the surrounding, unbroken rocks. The consortium of institutions will deploy seismometers to record explosions and earthquakes. The experiment will first decipher the structure of the crust in terms of P, S, and surface wave speeds, then interpret the wavespeed maps in terms of rock strength and crack density. The group will also measure the ground deformation over several years with GPS. These structures will be compared with the features noted with satellite deformation monitoring. The insights gatheredwill help understand why fault systems form as they do. More specifically, the spacing of faults and the frequency of earthquakes across the fault system in California is ripe for a deeper understanding, and this project will strive for progress in this direction.The investigators propose to integrate the expertise at UCLA, UCSD, and USC to systematically map the structural cross-section of the Calico and Pinto Mountain fault zones across profiles that exhibited anomalous strain in response to the Landers and Hector Mine earthquakes. They will deploy portable seismographs in both an active-source experiment to map the shallow fault structure and a passive-source experiment to image deeper structure. Their observations will test and extend previous InSAR modeling to better resolve the amplitude, width and depth of fault zone anomalies. This project will explore the structure and evolution of seismogenic faults in the Mojave using a variety of methods. The results will constrain the size of fault zone weakness and variations in strength across the earthquake cycle and lead to improved understanding of fault mechanics.This project supports educational programs at three universities, including graduate student research and field programs for undergraduates. Collaboration between institutions will be promoted by regular meetings of the PIs, students and postdocs to discuss relevant science and the state of the project. Results of this research will be widely disseminated through publications, conference presentations and media contacts, including a project website. This research will provide a better understanding of fault behavior, leading eventually to improved earthquake forecasting and reduced casualties and damage.