Metadata: Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 2018 Title: Seismic Reflection, EdgeTech SB-512i chirp profile images,USGS field activity 2017-003-FA, Mississippi River Delta front offshore of southeastern Louisiana (PNG images) Edition: 1.0 Geospatial_Data_Presentation_Form: raster digital data Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/F7X929K6 Publication_Information: Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts Publisher: U.S. Geological Survey, Coastal and Marine Geology Program Online_Linkage: https://doi.org/10.5066/F7X929K6 Online_Linkage: https://www.sciencebase.gov/catalog/item/5a958874e4b06990606a7cc8 Larger_Work_Citation: Citation_Information: Originator: Wayne E. Baldwin Originator: Seth D. Ackerman Originator: Charles R. Worley Originator: William W. Danforth Originator: Jason D. Chaytor Publication_Date: 2018 Title: High-resolution geophysical data collected along the Mississippi River Delta front offshore of southeastern Louisiana, U.S. Geological Survey Field Activity 2017-003-FA Edition: 1.0 Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/F7X929K6 Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Other_Citation_Details: Suggested citation: Baldwin, W.E., Ackerman, S.D., Worley, C.R., Danforth, W.W., and Chaytor, J.D, 2018, High-resolution geophysical data collected along the Mississippi River Delta front offshore of southeastern Louisiana, U.S. Geological Survey Field Activity 2017-003-FA: U.S. Geological Survey data release, https://doi.org/10.5066/F7X929K6. Online_Linkage: https://doi.org/10.5066/F7X929K6 Online_Linkage: https://www.sciencebase.gov/catalog/item/5a8c4bcbe4b00f54eb44044c Description: Abstract: High resolution bathymetric, sea-floor backscatter, and seismic-reflection data were collected offshore of southeastern Louisiana aboard the research vessel Point Sur on May 19-26, 2017, in an effort to characterize mudflow hazards on the Mississippi River Delta front. As the initial field program of a research cooperative between the U.S. Geological Survey, the Bureau of Ocean Energy Management, and other Federal and academic partners, the primary objective of this cruise was to assess the suitability of sea-floor mapping and shallow subsurface imaging tools in the challenging environmental conditions found across delta fronts (for example, variably distributed water column stratification and widespread biogenic gas in the shallow subsurface). Approximately 675 kilometers (km) of multibeam bathymetry and backscatter data, 420 km of towed chirp data, and 550 km of multichannel seismic data were collected. Varied mudflow (gully, lobe), prodelta morphologies, and structural features were imaged in selected survey areas from Pass a Loutre to Southwest Pass. Purpose: These PNG images represent approximately 420 km of chirp seismic-reflection data collected by the U.S. Geological Survey during cruise 2017-003-FA along the Mississippi River Delta front offshore of southeastern Louisiana. Images of each seismic profile were generated in order to provide portable and easily viewable alternatives to the SEGY versions of the data. Each profile image can be hotlinked to its corresponding trackline navigation contained within the Esri polyline shapefile '2017-003-FA_512i_Tracklines.shp'. Shotpoint index marks along the top of the PNG images correlate to the positions of 500 shot intervals within the Esri point shapefile '2017-003-FA_512i_500sht.shp'. Supplemental_Information: Additional information on the field activity is available from https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-003-FA. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20170521 Ending_Date: 20170524 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned. Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -89.554864 East_Bounding_Coordinate: -88.862675 North_Bounding_Coordinate: 29.285489 South_Bounding_Coordinate: 28.775983 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:5a958874e4b06990606a7cc8 Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: U.S. Geological Survey Theme_Keyword: USGS Theme_Keyword: Woods Hole Coastal and Marine Science Center Theme_Keyword: WHCMSC Theme_Keyword: Coastal and Marine Geology Program Theme_Keyword: CMGP Theme_Keyword: Bureau of Ocean Energy Management Theme_Keyword: BOEM Theme_Keyword: field activity number 2017-003-FA Theme_Keyword: seismic profile Theme_Keyword: seismic reflection Theme_Keyword: chirp Theme_Keyword: Edgetech Theme_Keyword: 512i Theme_Keyword: image Theme_Keyword: PNG Theme_Keyword: Marine Geology Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: oceans Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: seismic reflection methods Theme_Keyword: sub-bottom profiling Theme_Keyword: marine geophysics Theme_Keyword: marine geology Place: Place_Keyword_Thesaurus: None Place_Keyword: Gulf of Mexico Place_Keyword: Southeast Louisiana Place_Keyword: Mississippi River Delta Front Place_Keyword: Southwest Pass Place_Keyword: South Pass Place_Keyword: Pass a Loutre Stratum: Stratum_Keyword_Thesaurus: None Stratum_Keyword: sea floor Stratum_Keyword: seafloor Temporal: Temporal_Keyword_Thesaurus: none Temporal_Keyword: 2017 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. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Wayne E. Baldwin Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: Massachusetts Postal_Code: 02543-1598 Country: US Contact_Voice_Telephone: 508-548-8700 x2226 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: wbaldwin@usgs.gov Browse_Graphic: Browse_Graphic_File_Name: https://www.sciencebase.gov/catalog/file/get/5a958874e4b06990606a7cc8/?name=2017-003-FA_512i_Images_browse.jpg Browse_Graphic_File_Description: Thumbnail image of chirp seismic-reflection profile example from the Mississippi River Delta front offshore of southeastern Louisiana. Browse_Graphic_File_Type: JPEG Data_Quality_Information: Logical_Consistency_Report: Processed seismic data were converted to PNG format for ease of seismic trace display. Quality control was conducted during processing. Completeness_Report: Sections of tracklines where navigation was recorded but no seismic data were logged are not included such as during testing, some turns, and very short files. There are no Line-0001, Line-0004, Line-0016 or Line-0017. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Although navigation is not stored in the images, positional accuracy is relevant to the accuracy of these data. The EdgeTech SB-0512i subbottom profiler was mounted on a catamaran sled and towed at the sea surface approximately 40 m astern of the M/V Scarlett Isabella. The transducer depth below water line was 0.5 meters below catamaran floats. Navigation data for the 512i were collected using a Wide Area Augmentation System (WAAS) enabled Garmin Differential GPS (DGPS) receiver, which was located on the catamaran sled and connected to the acquisition computer via a serial cable. Positioning data were recorded in SonarWiz (version 6.05.0011) acquisition software, which logged positioning coordinates to individual trace headers SEG-Y format. WAAS enabled GPS horizontal positional accuracy is assumed to be within 2 m; however, horizontal position uncertainty increases with sonar and sled motion, which was not compensated for at the sonar transducer. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: Unpublished Material Title: 512i PNG image data Geospatial_Data_Presentation_Form: raster digital data Type_of_Source_Media: disc Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20170521 Ending_Date: 20170524 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: SEG-Y 512i data Source_Contribution: Chirp seismic data were collected using an EdgeTech Geo-Star FSSB sub-bottom profiling system and an SB-0512i towfish (0.5-12 kHz), which was mounted on a catamaran and towed astern of the R/V Point Sur of Gulfport, MS. Chesapeake Technology's SonarWiz (version 6.05.0011) seismic acquisition software was used to control the Geo-Star topside unit, digitally log trace data in the SEG-Y Rev. 1 format (IEEE floating point), and record GPS navigation coordinates to the SEG-Y trace headers (in arc seconds of Latitude and Longitude, multiplied by a scalar of 100). Data were acquired using shot rates between 250 and 750 milliseconds (ms), a 30-ms pulse length, and a 0.5 to 7.2 kHz frequency sweep. Traces were recorded with a 46-microsecond sample interval over lengths between approximately 180 and 700 ms. Process_Step: Process_Description: Scripts within SIOSEIS (version 2015.3.1) and Seismic Unix (version 4.2) were used to process SEG-Y data, create navigation files, and plot images. The processing flow and scripts used to produce navigation files including trackline shapefiles are summarized below and in the following processing steps. 1) SIOSEIS (version 2015.3.1) 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 was used to minimize cross talk from the multichannel seismic acquisition sources (boomer and sparker) with a two-trace median stack (trim 50 percent of the values furthest from the median amplitude) and improve water bottom picking. This script was used for all lines even when multi-channel acquisition was not simultaneously occurring, due to the improvements made to water bottom picks. 3) The script Read512i_mstk was used to read median filtered stacked and renumbered SEG-Y files, write a Seismic Unix file, and extract SEG-Y trace header information, including shot number, longitude, latitude, year, Julian day, and time of day (UTC). Header information from each SEG-Y file was saved to text files after an AWK (no version) filter was used to maintain the first and last shots, shots at multiples of 100, 500, and shots with unique navigation coordinates. Geographic coordinates (WGS 84) were converted to UTM zone 16 N coordinates (WGS 84) using Proj (version 4.6.0). End shots and shots at multiples of 100 may not have unique navigation coordinates. Separate text files containing the first and last shots and even 500 shot intervals were also saved. A 500 shot interval was chosen because it corresponds to the annotation interval provided along the top of the seismic-reflection profile images. Read512i_mstk called a Python script 512itoSQL17003.py, written by Wayne Baldwin, which imported the CSV files to a Spatialite (version 4.3.0) enabled SQLite (version 3.21.0) database. 4. 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. 5. The Seismic Unix script Plot512i_s creates a swell-filtered PNG image using ImageMagick (version 6.9.5-4) of each seismic line that is 12 inches high. Images show two-way travel time (seconds) along the y-axis (left margin) and shots along profile (labeled at 500 shot intervals) on the x-axis (along top of profile). Process_Date: 201712 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Wayne E. Baldwin Contact_Organization: U.S. Geological Survey Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical address Address: 384 Woods Hole Rd. City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Contact_Voice_Telephone: (508) 548-8700 x2226 Contact_Facsimile_Telephone: (508) 457-2310 Contact_Electronic_Mail_Address: wbaldwin@usgs.gov Process_Step: Process_Description: Added keywords section with USGS persistent identifier as theme keyword. Process_Date: 20200807 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: VeeAnn A. Cross Contact_Position: Marine Geologist Contact_Address: Address_Type: Mailing and Physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Contact_Voice_Telephone: 508-548-8700 x2251 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: vatnipp@usgs.gov Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Pixel Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: The PNG seismic reflection images can be hyperlinked to their corresponding trackline or shotpoint locations in ArcGIS using the shapefiles '2017-003-FA_512i_Tracklines.shp' or '2017-003-FA_512i_500sht.shp', respectively (available from the larger work citation). The images show two-way travel time (seconds) on the y-axis and distance along profile (annotation at 500 shot intervals) on the x-axis. Entity_and_Attribute_Detail_Citation: U.S. Geological Survey Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - ScienceBase Contact_Address: Address_Type: mailing and physical address Address: Federal Center Address: Building 810 Address: Mail Stop 302 City: Denver State_or_Province: CO Postal_Code: 80225 Contact_Voice_Telephone: 1-888-275-8747 Resource_Description: USGS data release 2017-003-FA 512i PNG imagery from the Mississippi River Delta front area: includes the zip archive 2017-003-FA_512i_Images.zip containing 55 PNG images named according to line convention with an '_s' appended to note swell-filter processing, the browse graphic 2017-003-FA_512i_Images_browse.jpg, and the Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata file 2017-003-FA_512i_Images_meta.xml. Distribution_Liability: 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. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: PNG Format_Version_Number: ImageMagick (version 6.9.5-4) Format_Specification: Portable Network Graphic (PNG) Format_Information_Content: The 7zip (version 16.04) file contains seismic-reflection profile images of EdgeTech SB-512i collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center along the Mississippi River Delta front and the associated metadata. File_Decompression_Technique: Use WinZip, 7zip, Peazip or pkUnzip Transfer_Size: 520 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/item/5a958874e4b06990606a7cc8 Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/5a958874e4b06990606a7cc8 Network_Resource_Name: https://doi.org/10.5066/F7X929K6 Access_Instructions: The first link is to the page containing the data, the second link downloads all data available from the page as a zip file, and the third link is to the publication landing page. Fees: none Technical_Prerequisites: These data can be viewed with any PNG image viewing software. The zip files must be uncompressed in order to view the images. Metadata_Reference_Information: Metadata_Date: 20200807 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Wayne E. Baldwin Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical Address: 384 Woods Hole Rd. City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Contact_Voice_Telephone: (508) 548-8700 x2226 Contact_Facsimile_Telephone: (508) 457-2310 Contact_Electronic_Mail_Address: wbaldwin@usgs.gov Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Time_Convention: local time