NSFGEO-NERC: Global ultralow-velocity zone properties from seismic waveform modeling

地球核幔边界区是研究地球动力学的重要区域，具有多种多样的非均质结构。超低速带（ULVZ）是CMB地震速度降低的区域，与热点火山活动、大火成岩省、核幔相互作用和大-低剪切速度省有关，因此在评估地球动力学方面至关重要。通常使用地震波形分析来研究ULVZ，但是由于建模权衡，这些研究遭受ULVZ参数的大的不确定性。与超低容量区的物理性质有关的基本问题仍然没有答案，包括其成分可变性、大小分布、相对于其他结构的位置以及三维几何形状。此外，只有一小部分CMB区域被探测到超低电压区。在这里，我们试图从各个角度从根本上重新评估ULVZ，并减少其属性，位置和成分的不确定性。

The Earth's core-mantle boundary (CMB) region is of critical importance for understanding Earth dynamics and harbors a wide variety of heterogeneous structures. Ultra-low velocity zones (ULVZs) are regions of reduced seismic velocities at the CMB, which have been associated with hot spot volcanism,Large Igneous Provinces, core-mantle interaction and Large-Low Shear Velocity Provinces and thus are essential in assessing Earth dynamics. ULVZs are typically studied using seismic waveform analysis, but these studies suffer from large uncertainties in ULVZ parameters due to modeling tradeoffs. Fundamental questions related to the physical nature of ULVZs remain unanswered, including their compositional variability, size distribution, location with respect to other structures, and 3-D geometry. Additionally, only a small fraction of the CMB area has been probed for ULVZs. Here, we seek to fundamentally reassess ULVZs from all angles, and reduce uncertainties in their properties, location, and composition.