Earthquake precursors and earthquake monitoring are always important in the earthquake research field, even if there is still debate about the existence of earthquake precursors. However, it is extremely difficult to observe the seismogenic environment of earthquakes directly. Laboratory rupture experiment is a useful technique to simulate and gain an insight into the complex mechanisms of earthquakes. Five marble samples with prefabricated cracks are used for uniaxial loading experiments to investigate whether there is a precursory signal before rock fracture and to simulate the rupture process of strike-slip fault. The existence of a precursory signal is confirmed by the coefficient of variation (CV) results, from which we can see two patterns which are known as seismicity acceleration and quiescence before an earthquake. Moreover, these CV findings are applied to determine the locations of large deformation sampling points on the rock surface at different loading stages. Similar results are obtained when we consider actual seismicity at the northern end of the San Andreas Fault in California, which provides crucial evidence to prove the existence of precursor characteristics. In this case, three kinds of seismic monitoring models are designed to find out how to monitor these characteristics more effectively.

中文翻译：

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预制裂缝岩石的非均质前兆特征及其对地震监测的意义

地震前兆和地震监测在地震研究领域一直很重要，即使关于地震前兆的存在仍然存在争议。然而，直接观测地震的发震环境极其困难。实验室破裂实验是模拟和深入了解地震复杂机制的有用技术。采用5个带有预制裂缝的大理岩样品进行单轴加载实验，研究岩石破裂前是否有前兆信号，模拟走滑断层的破裂过程。前兆信号的存在由变异系数 (CV) 结果证实，从中我们可以看到两种模式，称为地震活动加速和地震前静止。而且，这些 CV 结果用于确定不同加载阶段岩石表面大变形采样点的位置。当我们考虑加利福尼亚圣安德烈亚斯断层北端的实际地震活动时，得到了类似的结果，这为证明前兆特征的存在提供了重要证据。在这种情况下，设计了三种地震监测模型来找出如何更有效地监测这些特征。