Laboratory Studies of Spontaneous Earthquake Ruptures: Influence of Inhomogeneities

认识到传统工程断裂力学和地震学在方法上的异同，本项目描述了一个“实验地震学”的跨学科项目。该项目利用先进的诊断方法，其中一些是通过以前的研究经费开发的，来研究控制断层破裂的基本物理现象。它旨在解决地震学中有关驱动应力、断层强度和断层几何不均匀性对破裂过程的影响的一些突出问题。研究人员还打算加强实验室观测和复杂的自然地震之间的联系，这些地震经常发生在这种不均匀性存在的情况下。本研究的跨学科性质必然涉及到在各个学科中为许多目标分配优先级。特别是，两个主要特点体现在实验的设计。首先，实验设计的目的是尽可能与他们所模拟的地球物理系统相关。其次，设计尽可能保持基本，以便实时数据收集和分析可以对所审查的现象产生明确的理解。通常，沿地震断层的局部破裂情况是根据在远离震源的地方记录的波扰动推断出来的。然而，地震资料的反演并不能代替对破裂过程的直接现场观测。除了研究人员最近的工作和其他一些孤立的案例外，大多数断层行为的数值和分析模型都存在。这一研究有助于解决地震动力学中存在的许多争议。此外，预计拟议的研究计划将导致新的，令人兴奋的，也许是意想不到的物理现象的识别。

Recognizing the differences and similarities in approach between traditional engineeringFracture Mechanics and Seismology, this project describes an interdisciplinary program on "Experimental Seismology". This project utilizes advanced diagnostic methods, some of them developed through previous research funding, to study basic physical phenomena governing fault rupture. It aims to address some of the outstanding problems in Seismology pertaining to the influence of driving stress, fault strength and fault geometry inhomogeneities on the rupture process. The researchers also intend to strengthen the connection between laboratory observations and complex natural earthquakes which often occur in the presence of such inhomogeneities. The interdisciplinary nature of this research necessarily involves assigning priorities to the many goals within individual disciplines. In particular, two main characteristics are reflected in the design of the experiments. Firstly, the experimental design is intended to be as relevant as possible to the geophysical systems that they model. Secondly, the design is kept as basic as possible so that real-time data collection and analyses can produce, unequivocal, understanding regarding the phenomena under scrutiny. Typically, localized rupture conditions along earthquake faults are inferred from wave disturbances recorded at locations remote from the hypocenter. However, inversion of seismographic data is no substitute for direct in-situ observation on the rupture process. With the exception of the researchers recent work, and a few other isolated cases, mostly numerical and analytical models of fault behavior exist. This investigation may help resolve many controversies that exist in earthquake dynamics. In addition, it is expected that the proposed research program will result in the identification of new, exciting, and perhaps unexpected physical phenomena.