Mapping Mantle Structure

这项研究是对地幔进行的非常成功的地震体波研究的延续。现在的工作将集中在地幔的上300公里和下300公里（D层），这些区域似乎在地震速度上有最大的横向变化。这些信息对于地幔对流模型的解析至关重要，而地幔对流是板块构造和地震的主要驱动力。将通过PKP阶段的前期到达以及其他核心阶段（如sc， Sdiff， SKS等）的限制来调查D”。在夏威夷热点附近的地幔上部300公里处，将采用多重反射s波技术进行研究。美国和加拿大部分地区的岩石圈将通过Pn和Sn相进行研究。

This research is a continuation of highly successful seismic body wave investigations of the earth's mantle. Efforts now will be directed towards the upper 300 km and lower 300 km (D" layer) of the earth's mantle, regions that appear to have the most lateral variation in seismic velocities. This information is critical to resolution of models of convection in the mantle, the major driving force for plate tectonics and earthquakes. D" will be investigated by means of precursory arrivals to the PKP phase along with constraints from other core phases such as ScS, Sdiff, SKS, etc. The upper 300 km of the mantle around the Hawaiian Hotspot will be investigated with multiple bounce S-wave techniques. The lithosphere beneath portions of the U.S. and Canada will be investigated by means of Pn and Sn phases.