Stephen T. Bosse James G. Flocks Arnell S. Forde 2017 Multimedia presentation U.S. Geological Survey Data Release doi:10.5066/F7BV7DRT St. Petersburg, FL U.S. Geological Survey https://doi.org/10.5066/F7BV7DRT Stephen T. Bosse James G. Flocks Arnell S. Forde 2017 Multimedia presentation U.S. Geological Survey Data Series 1047 St. Petersburg, FL U.S. Geological Survey https://doi.org/10.3133/ds1047 The U.S. Geological Survey (USGS) Coastal and Marine Geology Program has actively collected geophysical and sedimentological data in the northern Gulf of Mexico for several decades, including shallow subsurface data in the form of high-resolution seismic-reflection profiles (HRSP). Prior to the mid-1990s most HRSP data were collected in analog format as paper rolls of continuous profiles up to 25 meters long. A large portion of this data resides in a single repository with minimal metadata. As part of the National Geological and Geophysical Data Preservation Program, scientists at the USGS St. Petersburg Coastal and Marine Science Center are converting the analog paper records to digital format using a large-format continuous scanner. This publication serves as an archive of seismic profiles with headers, converted Society of Exploration Geophysicists Y format (SEG-Y) files, navigation data, and geographic information system (GIS) data files for digitized boomer seismic-reflection data collected from the Research Vessel (R/V) Erda during two cruises in 1990 and 1991. The Erda 90-1 geophysical cruise was conducted in two legs. The first leg included seismic data collected from the Hancock County region of the Mississippi Sound (Erda 90-1_HC) from June 4 to June 6, 1990. The second leg included seismic data collected from the Petit Bois Pass area of Mississippi Sound (Erda 90-1_PBP) from June 8 to June 9, 1990. The Erda 91-3 cruise occurred between September 12 and September 23, 1991 and surveyed the Mississippi Sound region just west of Horn Island, Mississippi. To archive all digitized analog boomer seismic profile data and associated files collected from Hancock County, Petit Bois Pass, and west of Horn Island, Mississippi Sound, northern Gulf of Mexico during the ERDA 90-1, and ERDA 91-3 cruises. The USGS Saint Petersburg Coastal and Marine Science Center (SPCMSC) currently holds 13 major geophysical surveys from the northern Gulf of Mexico in its paper repository. A conservative estimate of 2,000 line-kilometers (km) of data is available. Paper copies of data are difficult and expensive to duplicate and share with other facilities, and cannot be analyzed using standard GIS and interpretative software. Conversion of this data into a usable digital format is necessary to archive the geologic information that otherwise might be lost, requiring additional redundant and very expensive marine-geophysical surveys. The USGS National Geological and Geophysical Data Preservation Program (NGGDPP, http://datapreservation.usgs.gov) addresses the need to preserve, catalog, and provide access to geological and geophysical data for scientific research and economic development. In addition to the current efforts under the NGGDPP, four geophysical investigations from the 1980s and 1990s were previously archived through a preservation project in collaboration with the Bureau of Ocean Energy Management (Harrison and others, 2007; Sanford and others, 2009a, b, c). The USGS-SPCMSC scans its analog HRSP holdings using a large-format continuous scanner. The analog to digital conversion process used for this report is similar to the processes used previously in Harrison and others, (2007) and Sanford and others, (2009a, b, c). The digital files are converted into Tagged Image File Format (TIFF) for standard accessibility by raster image processors. The TIFF images are also converted to the Society of Exploration Geophysicists Y format (SEG-Y) files. This standard non-proprietary format is the accepted industry standard for seismic data, and can be accessed by all major seismic data processing and interpretation systems. To accompany the HRSP, navigation and metadata files are generated for use in GIS, database and Internet Message Access Protocol (IMAP) services, and included in USGS data archives. The northern Gulf of Mexico is a passive continental margin, where minimal structural change to the shallow stratigraphy has occurred during the last few thousand years (Anderson and others, 2004). Therefore, subsurface data collected from this environment for the purposes of geologic assessment can be considered useful in perpetuity. The geologic information collected by the USGS in the northern Gulf of Mexico remains a valuable resource for sea floor and stratigraphic investigations, and is continuously revisited by researchers interested in Holocene and recent earth processes. For example, decades-old geologic data is commonly used in sediment resource studies in coastal Louisiana (for example, Kindinger and others, 2001; Kulp and others, 2002; Rogers and others, 2009) and previously collected datasets across the Mississippi-Alabama shelf have been used in recent geologic-framework assessments (Roberts and others, 2004; Greene and others, 2007; Flocks and others, 2011). This publication describes data collection and processing methods for seismic profiles created from analog boomer seismic-reflection data collected during three surveys (Erda 90-1_HC, Erda 90-1_PBP and Erda 91-3) in 1990 and 1991. The seismic data were collected using a single-channel Huntec boomer/benthos hydrophone system with Ocean Research Equipment (ORE) Geopulse power supply. The system consists of an electromagnetic sound source mounted on a catamaran sled towed behind the vessel at the water surface. The signal emitted from the sound source is received by a 5 m-long hydrophone streamer towed alongside the sled. The received signal is processed into response amplitudes via a topside computer running the acquisition software; the settings varied by cruise. The seismic data were printed onto paper rolls as two-dimensional profiles representing track length and depth (time). Geographic positioning of the system was collected using a long range navigation (LORAN) system and annotated onto the paper copies. 19900604 19900608 19910912 ground condition Complete None planned -89.6555 -88.2492 30.4302 30.0783 USGS Metadata Identifier USGS:f7c2a577-e749-4100-a117-10883b035ed4 ISO 19115 Topic Category geoscientificInformation oceans None Geology Coastal Marine Seismic reflection Society of Exploration Geophysicists SEG-Y BIM (Barrier Island Mapping) Navigation ERDA HC (Hancock County) PBP (Petit Bois Pass) USGS Thesaurus marine geology geology sediment transport ocean processes Geographic Names Information System (GNIS) Content United States of America Louisiana Mississippi Gulf of Mexico Alabama Hancock County Petit Bois Pass Mississippi Sound None. These data are held in the public domain. Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research. Stephen T. Bosse U.S. Geological Survey Geologist mailing and physical

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St. Petersburg FL 33701 USA (727) 502-8000 sbosse@usgs.gov Anderson, J.B., Rodriguez, A., Abdulah, K.C., Fillon, R.H., McKeown, H.A., and Wellner, J.S. 2004 Society for Sedimentary Geology 79 pages 1-24 https://mr.crossref.org/iPage?doi=10.2110%2Fpec.04.79.0001 Barry, K.M., Cavers, D.A., and Kneale, C.W. 1975 Geophysics v. 40, no. 2 pages 344-352 http://library.seg.org/doi/pdf/10.1190/1.1440530 Flocks, J.G., Ferina, N.F., and Kindinger, J.L. 2011 College Station, Texas, Texas A&M University Press 3 pages 157-173 https://muse.jhu.edu/book/1783 Greene, D.L., Jr., Rodriquez, A.B., and Anderson, J.B. 2007 Journal of Sedimentary Research 77 pages 139-158 http://jsedres.geoscienceworld.org/content/77/2/139 Harrison, A.S., Dadisman, S.V., Kindinger, J.L., Morton, R.A., Blum, M.D., Wiese, D.S., and Subino, J.A. 2007 U.S. Geological Survey Data Series 296 https://pubs.usgs.gov/ds/296/ Kindinger, J.L., Flocks, J.G., Kulp, M.A., Penland, S., and Britsch, L.D. 2001 U.S. Geological Survey Open-File Report 2001-384 69 pages https://pubs.er.usgs.gov/publication/ofr01384 Kulp, M.A., Howell, P.D., Adiau, S., Penland, S., Kindinger, J.L., and Williams, S.J. 2002 Gulf Coast Association of Geological Society Transactions 52 pages 573-582 http://archives.datapages.com/data/gcags/data/052/052001/0573.htm#a1 Roberts, H.H., Rillon, R.H., Kohl, B., Robalin, J.M., and Sydow, J.C. 2004 Society for Sedimentary Geology 79 pages 142-189 http://archives.datapages.com/data/sepm_sp/SP79/Depositional_Architecture_of_the_Lagniappe_Delta.pdf Rogers, B.E., Kulp, M.A., and Miner, M.D. 2009 Geo-Marine Letters 29 pages 379-394 http://link.springer.com/article/10.1007/s00367-009-0162-6 Sanford, J.M., Harrison, A.S., Wiese, D.S., and Flocks, J.G. 2009 U.S. Geological Survey Data Series 429 2009a https://pubs.usgs.gov/ds/429/ Sanford, J.M., Harrison, A.S., Wiese, D.S., and Flocks, J.G. 2009 U.S. Geological Survey Data Series 428 2009b https://pubs.usgs.gov/ds/428/ Sanford, J.M., Harrison, A.S., Wiese, D.S., and Flocks, J.G. 2009 U.S. Geological Survey Data Series 370 2009c https://pubs.usgs.gov/ds/370/ The validity or accuracy of analog boomer profiling data is highly qualitative and depends on equipment and operating condition variables. Visual inspection of the images rendered from the data did not show any major anomalies. This dataset is from two separate cruises with consistent instrument calibrations. These data are collected along tracklines (2-D) and are therefore inherently incomplete. As the seismic reflection data were acquired, the position of the vessel was recorded using a LORAN-C system. The accuracy of the LORAN-C varied from 528 to 1,320 feet (ft), with repeatable accuracy between 60 and 300 ft. Positions were recorded in latitude and longitude coordinates every 5 minutes and appear on the seismic profiles as incremental, hand-annotated vertical event marks. Navigation data were obtained as .dat files and saved as tab-delimitated text files. These data are not to be used for bathymetry. Two-way travel (TWT) times shown on the printable profile images are relative to local sea level at the time of data acquisition. Raw Data Scanning - The seismic data collected during each survey is currently located in the SPCMSC archives and arranged in cruise-specific storage boxes. The analog boomer data is in the form of 50 centimeter (cm)-wide paper rolls, paper fan-folds, and vellum rolls. The various rolls can be up to 20 m long and contain multiple seismic tracklines. The rolls contain the seismic profile image with pertinent collection characteristics annotated during acquisition, such as shot number and time and may also include environmental conditions and equipment details. Horizontal lines across the profiles represent two-way travel time milliseconds (ms), and vertical lines represent navigation fixes acquired and annotated as the survey was underway. The raw data was scanned on a Contex SD 3600 continuous-feed scanner. Using the NEXTimage 4 program (Contex), the scans were saved as 8-bit grey-scale TIFF files at 300 dots-per-inch (dpi) resolution. In order to minimize the final image file size for archiving, a batch conversion program was used to reduce the resolution to 210 dpi. The raw navigation data were imported into Esri ArcGIS version 10.3 as point data, converted to lines using the “make polylines from points” tool from the XTools Pro toolbar, and the attribute table was annotated with the cruise year. TIFF 2016 Stephen T. Bosse U.S. Geological Survey Geologist mailing and physical address

600 4th Street South

St. Petersburg FL 33701 (727) 502-8000 sbosse@usgs.gov Cropping - The scanned TIFF images were imported into Adobe Photoshop (Ps) Creative Cloud 2015 and blank edge areas were cropped out to further reduce file size. For rolls that included more than one line of seismic data, the file was separated into individual lines. Separation was completed by cropping everything except for the line of interest, determined by the raw navigation information, from the original scan and saving it as a new file with its associated line name. The file naming convention is CruiseID-DataAssociation_trackline#.tif. It includes the cruise identification (Erda91-3), data association, for example PWH (profiles with headers) or SEGY, and trackline number (sometimes this also includes a subsection letter after the line number for tracklines split between multiple rolls), which in full is seen as Erda91-3-SEGY_4.tif. TIFF 2016 Stephen T. Bosse U.S. Geological Survey Geologist mailing and physical address

600 4th Street South

St. Petersburg FL 33701 (727) 502-8000 sbosse@usgs.gov Headers - Each image of the scanned seismic profiles also includes a header with associated information including cruise- and line-specific information and processing details. The header files were created in Microsoft Word 2010, exported as PDF files, appended to the far left of the image frame in Adobe Photoshop, and then flattened onto the image to reduce file size. The final TIFF images with attached header files are available for download from Bosse and others (2017). 2016 CruiseID-PWH_trackline#.tif Stephen T. Bosse U.S. Geological Survey Geologist mailing and physical address

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St. Petersburg FL 33701 (727) 502-8000 sbosse@usgs.gov Correcting Scan Distortion - When scanning the vellum rolls, it was very difficult to ensure that the paper fed through the scanner perfectly straight. As a result, when the scanned file was brought into Adobe Photoshop, a straight reference line was placed over the 0 ms line (water level) on the scan. It is important that horizontal lines are perpendicular to the vertical lines on the scans or the image to SEG-Y conversion will not be accurate. The distortion was corrected by using the Rectangular Marquee Tool in Adobe Photoshop to select and create a new layer of the distorted area of the scan. A skewed transform was performed and the corrected images were saved into a new folder without layers (flattened) to reduce file size. TIFF 2016 Stephen T. Bosse U.S. Geological Survey Geologist mailing and physical address

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St. Petersburg FL 33701 (727) 502-8000 sbosse@usgs.gov Image to SEG-Y - The scanned, distortion-corrected images were converted to digital SEG-Y (.seg) format (revision 0) (Barry and others, 1975) using the proprietary software ImageToSEGY 2.2 (Chesapeake Technology). The scanned images were opened in ImageToSEGY and the export area was defined by assigning values to the top, bottom, left, and right pixel locations using the imaged water surface (0 ms), maximum two-way travel time (TWT; 112.5 ms) and raw navigation data for each line. Trace amplitudes in the scanned profiles are represented by pixels, so each pixel becomes a trace sample and the sample rate of the converted SEG-Y version is the record length divided by the number of vertical pixels in the profile. For example, if the profile is 4,435 pixels vertically and the two-way travel time is 112.5 ms, then the sample rate for the SEG-Y file version is 0.000025 s. SEG 2016 CruiseID-SEGY_trackline#.seg Stephen T. Bosse U.S. Geological Survey Geologist mailing and physical address

600 4th Street South

St. Petersburg FL 33701 (727) 502-8000 sbosse@usgs.gov Added keywords section with USGS persistent identifier as theme keyword. 20201013 U.S. Geological Survey VeeAnn A. Cross Marine Geologist Mailing and Physical

384 Woods Hole Road

Woods Hole MA 02543-1598 508-548-8700 x2251 508-457-2310 vatnipp@usgs.gov 0.0197879842 0.0227644092 Decimal degrees North American Datum 1983 GRS_1980 6378137.0 298.257222101 Erda_XXXX_CruiseTracklines.shp Shapefile containing seismic profile data USGS FID Feature ID Esri Sequential unique whole numbers that are automatically generated Shape Feature geometry Esri Polyline Line_id Trackline or profile identifier USGS Character string representing unique cruise ID and track line number Year The year the cruise study was conducted USGS 1990 1991 Navigation_Erda_XXX.txt Text file containing navigation data USGS Long Longitude USGS -89.6555 -88.2492 Decimal Degrees Lat Latitude USGS 30.0783 30.4302 Decimal Degrees Shot A fixed point along the trackline USGS 0 81 Time The time each shot was taken, in military time USGS 83600 225500 JD Julian Calendar Day USGS 165 266 Line_id Trackline or profile identifier USGS Character string representing unique cruise ID and track line number Stephen T. Bosse U.S. Geological Survey Geologist mailing and physical

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St. Petersburg FL 33701 USA (727) 502-8000 sbosse@usgs.gov This report is available online. The SEG-Y files are downloadable from the Coastal and Marine Geoscience Data System. Downloadable data This publication was prepared by an agency of the United States Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. zip archive The SEG-Y rev. 0 format (Barry and others, 1975) presented here consists of the following: a 3,600-byte reel identification header, with the first 3,200 bytes consisting of an ASCII header block followed by a 400-byte binary header block, both of which include information specific to line and reel number; a trace data block that follows the reel identification header, with the first 240 bytes of each trace block consisting of the binary trace identification header; and seismic data samples that follow the trace identification header. Unzip 6720 https://coastal.er.usgs.gov/data-release/doi-F7BV7DRT/data/Profileswithheaders_Erda_90-1_HC.zip https://coastal.er.usgs.gov/data-release/doi-F7BV7DRT/data/SEGY_Erda_90-1_HC.zip https://coastal.er.usgs.gov/data-release/doi-F7BV7DRT/data/Navigation_Erda_90-1_HC.zip https://coastal.er.usgs.gov/data-release/doi-F7BV7DRT/data/CruiseTracklines_Erda_90-1_HC.zip https://coastal.er.usgs.gov/data-release/doi-F7BV7DRT/data/Profileswithheaders_Erda_90-1_PBP.zip https://coastal.er.usgs.gov/data-release/doi-F7BV7DRT/data/SEGY_Erda_90-1_PBP.zip https://coastal.er.usgs.gov/data-release/doi-F7BV7DRT/data/Navigation_Erda_90-1_PBP.zip https://coastal.er.usgs.gov/data-release/doi-F7BV7DRT/data/CruiseTracklines_Erda_90-1_PBP.zip https://coastal.er.usgs.gov/data-release/doi-F7BV7DRT/data/Profileswithheaders_Erda_91-3.zip https://coastal.er.usgs.gov/data-release/doi-F7BV7DRT/data/SEGY_Erda_91-3.zip https://coastal.er.usgs.gov/data-release/doi-F7BV7DRT/data/Navigation_Erda_91-3.zip https://coastal.er.usgs.gov/data-release/doi-F7BV7DRT/data/CruiseTracklines_Erda_91-3.zip None, if obtained online; otherwise, prices vary. Use of SEG-Y data requires specialized seismic processing software, such as public domain software Seismic Unix (http://www.cwp.mines.edu/cwpcodes/index.html). 20201013 Stephen T. Bosse U.S. Geological Survey Geologist mailing and physical

600 4th Street South

St. Petersburg FL 33701 USA (727) 502-8000 sbosse@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998