A vertical seismic reflection profile (VSP) experiment was conducted aboard the JOIDES RESOLUTION at DSDP Site 504B (Costa Rica Rift) during the ODP Leg 111. The data acquisition phase of the VSP experiment was supported by the U.S. Shipboard Science Support Program. The specific scientific objectives of the VSP experiment were: a) to determine the downgoing, direct wave seismic travel time curve for the interval of oceanic crust penetrated by the borehole in order to derive a detailed velocity depth profile; b) to compute a high resolution, upgoing wave vertical reflection seismogram for the oceanic crust Layers 2 and 3, as well as the Moho and upper mantle; c) to precisely calibrate the VSP-derived reflection seismogram and velocity-depth profile with the borehole lithology and other well-logging information; and d) to correlate the VSP reflection seismogram and well-logging information with the regional surface ship multichannel seismic (MCS) reflection profiles. Initial processing of the field data shows that the quality of the data is very high. In this award, Dr. Phillips will complete processing and interpretation of this high quality data- set. Dr. Phillips is an experienced scientist and the objectives of the experiment will be completed at the end of this project.
