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PNG images of each seismic profile were generated in order to incorporate images of the seismic profiles into Geographic Information System (GIS) projects and data archives. These data represent approximately 745 km of chirp seismic-reflection data collected by the U.S. Geological Survey during cruise 2014-009-FA offshore of Fire Island, NY. Each profile image can be hotlinked to its corresponding trackline navigation contained within the Esri polyline shapefile '2014-009-FA_512i_Tracklines.shp'. Shotpoint index markers along the top of the PNG images correlate to the positions of 500 shot intervals within the Esri point shapefile '2014-009-FA_512i_500sht.shp' (available from the larger work).
1. SIOSEIS (version 2013.1.1) was used to read SEG-Y files, renumber shots starting from one, extract the envelope-detected trace, and write out new SEG-Y files. The original shot numbers, which were assigned by SonarWiz sequentially over the duration of an acquisition session despite SEG-Y file changes, are preserved in the raw SEG-Y data.
2. The SIOSEIS script Sio_medianstk applied a two-trace median stack (trim 50 percent of the values furthest from the median amplitude) to improve subsequent water bottom picking.
3. The SIOSEIS script siothresh_pltwbt was used to pick the water-bottom time from the median stacked SEG-Y files, apply a swell filter to smooth water-bottom time picks and shift the trace data by the difference between the smoothed and unsmoothed water bottom time before writing the shifted trace data to a new SEG-Y file.
4. The Seismic Unix script Plot512i_s creates a swell-filtered PNG image of the seismic profile using supsimage and ImageMagick (version 6.6.1). The resultant images are 29 inches high and contain an 80 millisecond (two-way travel time) window of data. Images show two-way travel time (seconds) along the y-axis (left margin) and distance along profile (in 500 shot intervals, corresponding to the point features in the shapefile 2014-009-FA_512i_500sht.shp) on the x-axis (along top of profile).
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Are there legal restrictions on access or use of the data?Access_Constraints: none
Use_Constraints:Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
| Data format: | The WinZip (version 14.0) files contain seismic-reflection profile images of EdgeTech SB-512i collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center offshore of Fire Island, NY in 2014 and the associated metadata. in format PNG (version ImageMagick (version 6.6.1)) Portable Network Graphic (PNG) Size: 57.5 |
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| Network links: |
https://cmgds.marine.usgs.gov/data/field-activity-data/2014-009-FA/data/seismics/2014-009-FA_512i_Images.zip https://doi.org/10.5066/F7FF3QTQ https://cmgds.marine.usgs.gov/data/field-activity-data/2014-009-FA/ |
These data can be viewed with any PNG image viewing software. The zip files must be uncompressed in order to view the images.
