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

9529075马萨诸塞州伍兹霍尔海洋研究所的这些研究人员将迅速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异性。在这种环境下进行的实验中，很少出现高质量的横波到达，当与已经利用这些数据进行的纵波研究相结合时，横波对岩石的性质提供了重要的限制。这些数据是作为垂直地震剖面仪(VSP)实验的一部分收集的，接收器位于深海钻井项目504B孔，这是有史以来对大洋地壳进行的最深穿透。它们提供了以比任何其他地点更高的分辨率确定地壳性质的机会。该项目是在认识到这些数据中的高质量横波到达后提出的，调查人员开发了新的分析技术，使首次对井眼岩性(根据钻井结果)、由现场测井得出的井眼孔隙度以及VSP数据中包含的纵横速度信息的一致研究成为可能。***

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. ***