Collaborative Research: Generation of Rock Damage and Localization of Seismicity Before Large Earthquakes

大地震是如何产生的，以及如何预测它们，仍然是尚未解决的基本科学问题。它们对人类社会具有强烈的影响。大地震可能导致生命损失，毁灭性破坏，并引发海啸，火灾和山体滑坡等其他危险。该项目旨在提高对地震动力学的理解和预测大事件的能力。 其关键是跟踪地震破裂前地震形变的渐进局部化过程。为此，研究人员将联合收割机新的统计技术与来自不同构造环境的高分辨率地震目录相结合。它们解释了压裂实验和变形局部化物理模拟的数据。该项目还为两名研究生提供支助和培训。其结果有助于改进地震危险性评估。 这些调查工作旨在为跟踪大地震的准备过程制定一个定量操作框架。这是通过遵循从体积中的分布故障到最终产生大地震的局部剪切带的变形的渐进演化来实现的。该研究考虑整个体积的变形，而不是预先存在的断层或断层组。该分析与统一的区域分析和不同的空间-时间-能量尺度上的数千个地震群的解释相关联，而无需回顾性地选择分析区域。该项目开发、测试和实施了一个综合多信号程序，该程序综合了不同的地震观测结果，可用于估计大地震的临近时间。所开发的工具和结果将对认识地震活动性和分析活动构造环境中的地震危险性产生重要影响。该研究可以为地震物理学和地震危险性的其他观测、实验和理论研究提供信息并产生影响。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

How large earthquakes are generated, and how to forecast them, remain fundamental unsolved scientific questions. They have strong implications for human societies. Large earthquakes can result in loss of life, devastating destruction, and trigger additional hazards such as tsunamis, fires, and landslides. This project aims to improve the understanding of earthquake dynamics and ability to forecast large events. Its key aspect is to track the progressive localization of seismic deformation preceding the earthquake rupture. With this aim, the researchers combine novel statistical techniques with high-resolution earthquake catalogs from different tectonic environments. They account for data from fracturing experiments and physical modeling of deformation localization. The project also provides support and training for two graduate students. Its outcomes contribute to improve earthquake hazard assessment. The investigations work to develop a quantitative operational framework for tracking the preparation processes of large earthquakes. This is done by following the progressive evolution of deformation from distributed failures in a volume to localized shear zones culminating in generation of large earthquakes. The research considers deformation in entire volumes rather than on pre-existing faults or sets of faults. The analysis is associated with uniform regional analysis and interpretation of thousands of earthquake clusters on different space-time-energy scales, without retrospective selection of the analyzed zones. The project develops, tests, and implements an integrated multi-signal procedure synthesizing different seismic observations that may be used to estimate the approaching time of large earthquakes. The developed tools and results can have significant impact on understanding of seismicity and analysis of seismic hazard in active tectonic environments. The research can inform and impact additional observational, experimental, and theoretical studies on earthquake physics and seismic hazard.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.