Studies of Global Seismicity and Earth's Structure

9805172 Dziewonski这项研究涉及与地球结构和地震性质有关的广泛问题。 将测试三维速度结构反演方法的不均匀射线路径分布的影响。 3D样条将用于将高分辨率模型连接到全球模型。将继续进行绘制岩石圈和软流圈各向异性结构的工作。 将对410公里和660公里不连续面的地形图进行改进。 将研究内核各向异性的空间变化，特别是其对内核超旋转估计的影响。 对于地震，广泛使用的CMT（质心矩张量）分析和“快速CMT”确定和传播将得到改进和扩展，以多事件/较小地震的能力，低频震源谱反演技术将得到改进。 这项研究是国家地震减灾计划的一个组成部分。

9805172DziewonskiThis research addresses a broad range of questions related to earth structure and the nature of earthquakes. 3-D velocity structure inversion methods will be tested for the influence of uneven ray-path distribution. 3-D splines will be used to join high-resolution models to global models. Work will continue on the mapping of anisotropic structure in the lithosphere and asthenosphere. A refinement will be done of the mapping of topography for the 410 and 660 km discontinuities. The spatial variation of anisotropy in the inner core will be investigated, especially with respect to its influence on estimates of the super-rotation of the inner core. For earthquakes, the widely used CMT (Centroid Moment Tensor) analysis and "Quick CMT" determination and dissemination will be improved and expanded to multiple-event/smaller earthquake capability, and the low-frequency earthquake source spectrum inversion techniques will be improved. This research is a component of the National Earthquake Hazard Reduction Program.