Development and Application of the Back-Projection Techinque for Detailed Earthquake Rupture Modelling

该项目评估了地震台阵数据反投影获得的地震属性的稳健性和分辨率，并研究了提高成像能力的方法。破裂模型，特别是其速度和持续时间，是预测地面运动的主要因素之一。它也是研究地震引发、传播和终止的物理学中的一个关键因素。尽管如此重要，但破裂模型目前可用于少数经过充分研究的事件，如1992年加州兰德斯地震。来自密集地震阵列的大量高质量数据为解开详细的地震破裂过程提供了机会，反投影分析可能会产生一系列能量辐射和传播模型。该方法可以应用于任何阵列，但该项目侧重于来自日本高灵敏度地震台网的数据。将该方法应用于该数据集，提供了对2004年苏门答腊-安达曼和2005年尼亚斯地震的范围和持续时间等性质的限制。虽然这些结果证明了该技术和高质量阵列数据的力量，但该方法的不确定性和对其他地震的适用性的估计还没有得到充分的探索。该项目解决了这些问题，并研究了改进反投影程序的战略。该项目的目的是使我们正式了解该方法的能力和局限性，并通过近乎实时的地震探测和特征确定其在减轻灾害方面的可行性。在更广泛的影响中，包括对研究生和本科生的支持和教育。

This project evaluates the robustness and resolution of earthquake properties obtained from back-projection of seismic array data, and examines methods for improving the imaging ability. A rupture model, especially its speed and duration, is one of the main ingredients for predicting ground motion. It is also a key factor in studies of the physics of earthquake initiation, propagation, and termination. Despite such importance, rupture models are currently available for a limited number of well-studied events such as the 1992 Landers, California earthquake. A large number of high-quality data from a dense seismic array introduces an opportunity for unraveling detailed earthquake rupture processes, and the back-projection analysis can potentially lead to a catalog of energy radiation and propagation models. The method could be applied to any array, but this project focuses on data from the High Sensitivity Seismograph Network in Japan. Application of the method to this data set has provided constraints on properties such as extent and duration of the 2004 Sumatra-Andaman and 2005 Nias earthquakes. While these results demonstrate the power of the technique and high-quality array data, the estimates of uncertainty and applicability of the method to other earthquakes have not been fully explored. This project addresses these issues, and investigates strategies for improving the back-projection procedure. The aim of the project is to formalize our understanding of the capability and limitations of the method as well as determining its feasibility in hazard mitigation through detection and characterization of earthquakes in near real time. Among the broader impacts are the support and education of a graduate student and an undergraduate.