Centroid Moment Tensor Solutions for Intermediate-Depth Earthquakes from the Pre-Digital Era

小行星9706152 这项研究是为了扩展一个非常成功的项目，在数字全球地震网络安装之前，从模拟记录的深震中恢复地震数据。 以前的工作主要集中在1976年之前300-700公里深度范围内的地震。 这项工作将集中于125-300公里深度的深层事件。 因此，哈佛大学的焦点机制目录将在时间上向后延伸，以显著增加时间和空间上的统计采样密度。 将使用相同的哈佛算法对反投影数据进行焦点机制反演。 据设想，将获得约200个新的质心矩张量解;这将使有关深度和大小窗口中的震源可靠定量估计数据集的规模增加一倍。 这些新的结果将提供强大的新的洞察力的问题，如断层的起源在中深地震的矿物学转换，其分布在空间和时间的关系，当地的地质特征，并提高我们的理解，其复发模式，一个特别重要的课题，因为几个中深地震已导致严重的生命损失。 这项研究是国家地震减灾计划的一个组成部分。 ***

9706152 Okal This research is to extend a highly successful project to recover seismic data from analog recordings of deep earthquakes prior to the digital Global Seismic Network installation. Prior work concentrated on earthquakes in the depth range of 300-700 km prior to 1976. This effort will concentrate on deep events between 125-300 km in depth. Thus, the Harvard University focal mechanism catalogue will be extended back in time to increase significantly the statistical sampling density in time and space. Focal mechanism inversions will be done on the back-projected data using the same Harvard algorithm. It is envisioned that about 200 new centroid moment tensor solutions will be obtained; this would double the size of the data set of reliable, quantitative estimates of earthquake sources in the relevant windows of depth and size. These new results will provide powerful new insight into problems such as the origin of faulting in intermediate depth earthquakes in relation to mineralogical transformations, their distribution in space and time in relation to local geological features, and improve our understanding of their recurrence patterns, an especially important topic, since several intermediate earthquakes have resulted in severe loss of life. This research is a component of the National Earthquake Hazard Reduction Program. ***