Analysis and Interpretation of Shear Wave VSP Data at DSDP Hole 504B

来自马萨诸塞州伍兹霍尔海洋研究所的这些研究人员将研究东太平洋哥斯达黎加裂谷地区现有的地震横波记录，以研究玄武岩海底825米以上的声学和物理性质的变化。在这种环境下进行的实验中，很少出现高质量的横波到达，当与已经从这些相同数据中进行的纵波研究相结合时，横波提供了对岩石性质的重要约束。这些数据是作为垂直地震剖面仪（VSP）实验的一部分收集的，接收器位于深海钻探项目504B孔，这是迄今为止最深的海洋地壳穿透。它们提供了以比任何其他地点更高的分辨率定义地壳性质的机会。在这些数据中发现了高质量的横波到达后，研究人员提出了该项目，并开发了新的分析技术，使首次同时研究井眼岩性（来自钻井结果）、井眼孔隙度（来自原位测井）以及VSP数据中包含的压缩和剪切速度信息成为可能。＊＊＊

9529075 Swift These investigators from Woods Hole Oceanographic Institution in Massachusetts will study existing recordings of seismic shear waves from the Costa Rica Rift region in the eastern Pacific Ocean to study the variability of acoustic and physical properties of the upper 825 meters of the basaltic ocean floor. The presence of good quality shear wave arrivals is rare in experiments carried out in this environment, and when combined with the compressional wave studies which have already been carried out from these same data, the shear waves provide important constraints on the rock properties. The data were collected as part of a vertical seismic profiler (VSP) experiment with receivers located within Deep Sea Drilling Project hole 504B, the deepest penetration ever made into the ocean crust. They provide an opportunity to define crustal properties at higher resolution than has been possible at any other location. The project was proposed following the recognition of good quality shear wave arrivals in these data, and the investigators have developed new analytical techniques which make possible the first coincident study of borehole lithology (from drilling results), borehole porosity derived from in-situ logging, and the compressional and shear velocity information which is contained in the VSP data. ***