Studies of Global Seismicity and Earth's Structure

[805172] dziewonski这项研究解决了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对射线路径分布不均匀的影响。三维样条将用于将高分辨率模型与全局模型连接起来。岩石圈和软流圈各向异性结构的测绘工作将继续进行。将对410公里和660公里不连续区域的地形测绘进行细化。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，将改进目前广泛使用的CMT（质心矩张量）分析和“快速CMT”测定和传播，并扩展到多事件/小地震能力，改进低频震源谱反演技术。这项研究是国家减少地震危害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.