CDP navigation for processed multi-channel seismic reflection data from the U.S. Mid-Atlantic margin (EN555, 2015)

This data set is the Common Depth Point (CDP) navigation files for 30 processed high-resolution multichannel seismic reflection lines acquired by the U.S. Geological Survey Woods Hole Coastal and Marine Science Center in 2015 on R/V Endeavor, cruise EN555, with a towed sparker source. The data were collected on lines oriented mostly down the continental slope from 100 to 2000 meters water depth or parallel to the continental shelf. The source was the USGS Woods Hole Applied Acoustics Delta Sparker attached to a surface-towed sled. The source was operated at 2.4 kJ and usually fired at 5 s intervals. Seismic reflections were recorded using the 72-channel Geometrics GeoEel liquid filled streamer (nine 50-m-long active sections; total length 555 m) with group spacing of 6.25 m and depth control using birds. For seismic navigation, the USGS used its own GPS equipment (Hemisphere antenna) mounted on the 01 deck. Positions were recorded using UTM zone 18N and the WGS84 datum. There was no GPS tail buoy on the streamer. Individual seismic shot data (SEG-D data and GPS coordinates) were recorded with Geometrics acquisition seismic software with 0.5 ms sampling and record length of 4.5 s. SEG-Y files sorted to CDP gathers were imported to the Seismic Unix seismic processing software, where various processing steps were completed. Using Matlab, the CDP coordinates were smoothed with a Savitsky-Golay filter over 7 points in the x-coordinate and 9 points in the y-coordinate. These data files are in ASCII format and include a header. In these files, CDP positions are reported both in arcseconds (UTM18) and converted to geographic coordinates. CDP positions have estimated uncertainty of 20 m along the line and 30 m perpendicular to the line. Detailed acquisition and processing parameters are described in the associated documents. Funding was provided to the USGS Gas Hydrates Project through DOE NETL interagency agreements DE-FE000291 and DE-FE0005806.