Metadata: Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 20200409 Title: Chirp seismic reflection - shotpoints, tracklines, profile images, and SEG-Y traces for EdgeTech SB-512i chirp data collected during USGS field activity 2017-002-FA. Edition: 1.0 Geospatial_Data_Presentation_Form: digital data Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P9Y1MSTN 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/P9Y1MSTN Online_Linkage: https://www.sciencebase.gov/catalog/item/5e1e318fe4b0ecf25c610daf Larger_Work_Citation: Citation_Information: Originator: Wayne E. Baldwin Originator: Eric M. Moore Originator: Charles R. Worley Originator: Alex R. Nichols Originator: Carolyn D. Ruppel Publication_Date: 2020 Title: Marine Geophysical Data Collected to Support Methane Seep Research Along the U.S. Atlantic Continental Shelf Break and Upper Continental Slope Between the Baltimore and Keller Canyons During U.S. Geological Survey Field Activities 2017-001-FA and 2017-002-FA. Edition: 1.0 Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P9Y1MSTN Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Other_Citation_Details: Suggested citation: Baldwin, W.E., Moore, E.M., Worley, C.R., Nichols, A.R., and Ruppel, C.D., 2020, Marine Geophysical Data Collected to Support Methane Seep Research Along the U.S. Atlantic Continental Shelf Break and Upper Continental Slope Between the Baltimore and Keller Canyons During U.S. Geological Survey Field Activities 2017-001-FA and 2017-002-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P9Y1MSTN. Online_Linkage: https://doi.org/10.5066/P9Y1MSTN Online_Linkage: https://www.sciencebase.gov/catalog/item/5e179176e4b0ecf25c59f97a Description: Abstract: In spring and summer 2017, the U.S. Geological Survey’s Gas Hydrates Project conducted two cruises aboard the research vessel Hugh R. Sharp to explore the geology, chemistry, ecology, physics, and oceanography of sea-floor methane seeps and water column gas plumes on the northern U.S. Atlantic margin between the Baltimore and Keller Canyons. Split-beam and multibeam echo sounders and a chirp subbottom profiler were deployed during the cruises to map water column backscatter, sea-floor bathymetry and backscatter, and subsurface stratigraphy associated with known and undiscovered sea-floor methane seeps. The first cruise, known as the Interagency Mission for Methane Research on Seafloor Seeps and designated as field activity 2017-001-FA, was conducted from May 4 to May 11, 2017, and acquired geophysical data to support remotely operated vehicle exploration of seep sites using the Global Explorer, which is operated by Oceaneering International, Inc. Geophysical operations during cruise 2017-002-FA from August 25 to September 6, 2017, were also focused on mapping water column methane plumes, sea-floor seep sites, and subseafloor strata, but primarily supported conductivity, temperature, and depth instrument deployment, surface-water methane-concentration mapping, and water-sampling operations as part of a collaborative study with the University of Rochester of the effect of methane seepage on ocean water biogeochemistry. The National Oceanic and Atmospheric Administration’s Office of Ocean Exploration and Research partially sponsored cruise 2017-001-FA, and the U.S. Department of Energy partially sponsored both cruises. Purpose: This dataset contains shotpoint and trackline navigation, profile images, and raw SEG-Y trace data for approximately 222 km of EdgeTech 512i chirp seismic-reflection data collected by the U.S. Geological Survey during USGS field activity 2017-002-FA (also referred to as HRS1713) along the U.S. Atlantic continental shelf break and upper continental slope between Accomac and Keller Canyons. Images of each seismic profile were generated in order to provide portable and easily viewable alternatives to the SEG-Y versions of the data. Each profile image can be hyperlinked to its corresponding trackline navigation contained within the Esri polyline shapefile '2017-002-FA_SB512iTracklines.shp'. Shotpoint index and tick marks along the top of the PNG images correlate to the positions of 100 shot intervals within the Esri point shapefile '2017-002-FA_SB512i_sht100.shp'. This information allows for spatial correlation of chirp seismic-reflection profiles images with other geophysical and sample data for investigating sea-floor morphology and stratigraphy in the area. Supplemental_Information: Support for 2017-002-FA was provided to the USGS and the University of Rochester by DOE through interagency agreement DE-FE0026195 and grant DE-FE0028980. Additional information on the field activity is available from https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-002-FA. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20170826 Ending_Date: 20170905 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -74.858706 East_Bounding_Coordinate: -74.146661 North_Bounding_Coordinate: 37.540206 South_Bounding_Coordinate: 35.512023 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:5e1e318fe4b0ecf25c610daf 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 Hazards and Resources Program Theme_Keyword: CMHRP Theme_Keyword: Department of the Interior Theme_Keyword: DOI Theme_Keyword: Department of Energy Theme_Keyword: DOE Theme_Keyword: University of Rochester Theme_Keyword: field activity number 2017-002-FA Theme_Keyword: HRS1713 Theme_Keyword: R/V Hugh R. Sharp Theme_Keyword: shapefile Theme_Keyword: trackline navigation Theme_Keyword: seismic navigation Theme_Keyword: seismic reflection Theme_Keyword: seismic profile Theme_Keyword: SEG-Y traces Theme_Keyword: chirp Theme_Keyword: EdgeTech Theme_Keyword: SB-512i Theme_Keyword: image Theme_Keyword: PNG Theme_Keyword: marine geology Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: location Theme_Keyword: geoscientificInformation Theme_Keyword: oceans Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: seismic reflection methods Theme_Keyword: sub-bottom profiling Theme_Keyword: marine geophysics Theme_Keyword: marine geology Theme_Keyword: navigational data Theme_Keyword: geospatial datasets Place: Place_Keyword_Thesaurus: None Place_Keyword: United States of America Place_Keyword: Atlantic Ocean Place_Keyword: Atlantic Margin Place_Keyword: Accomac Canyon Place_Keyword: Washington Canyon Place_Keyword: Norfolk Canyon Place_Keyword: Keller Canyon Place_Keyword: Chincoteague Ridge 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 distributable 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 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/5e1e318fe4b0ecf25c610daf/?name=2017-002-FA_SB512i_browse.jpg Browse_Graphic_File_Description: Example chirp seismic-reflection profile image. Browse_Graphic_File_Type: JPG Cross_Reference: Citation_Information: Originator: Leonte, M. Originator: Ruppel, C. D. Originator: Ruiz‐Angulo, A. Originator: Kessler, J. D. Publication_Date: 2020 Title: Surface methane concentrations along the Mid‐Atlantic Bight driven by aerobic subsurface production rather than seafloor gas seeps. Edition: 1.0 Geospatial_Data_Presentation_Form: document Series_Information: Series_Name: Journal of Geophysical Research: Oceans Issue_Identification: vol. 125 Publication_Information: Publication_Place: Washington, DC Publisher: American Geophysical Union Publications Online_Linkage: https://doi.org/10.1029/2019JC015989 Data_Quality_Information: Logical_Consistency_Report: Chirp seismic-reflection data were collected during overnight operations (generally between approximately 24:00 and 10:00 UTC) on Aug 26, Sept. 1, and Sept. 3 - 5. '2017-002-FA_SB-512i_sht100.shp' contains the first (1), last (x), and 100-interval shotpoints for each seismic trackline, and '2017-002-FA_SB-512i_shtnav.csv' contains all unique shot point navigation. The attribute fields 'LineName' and 'ImageName' for each polyline feature in '2017-002-FA_SB-512iTracklines.shp' correspond to the SEG-Y data files in '2017-002-FA_SB512i_SegyData.zip' and the PNG profile images in "2017-002-FA_SB512i_Images.zip", respectively. One SEG-Y file, and PNG image exists for each feature. 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. Testing files Line-0001 through Line-0003 are not included in the data release. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The EdgeTech SB-512i subbottom profiler was towed from the a-frame of the R/V Hugh R. Sharp with the transducer between 10 and 19 m below the water line, and approximately 60 meters astern of the DGPS antenna mounted on the aft 01 deck handrail. Navigation data for the SB-512i were collected using a Hemisphere GPS receiver. Positioning data were recorded using SonarWiz 6 (version 6.05.001) acquisition software, which logged coordinates to individual trace headers in SEG-Y format. DGPS horizontal positional accuracy is assumed to be within 3 m; the layback position of the transducer relative to the GPS antenna was accounted for during processing. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: unpublished material Title: SB-512i SEG-Y trace data Geospatial_Data_Presentation_Form: digital data Type_of_Source_Media: disc Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20170826 Ending_Date: 20170905 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: SEG-Y SB-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 towed from the A-frame of the R/V Hugh R. Sharp with the transducer between 10 and 19 m below the water line, and approximately 60 meters astern of the GPS antenna mounted on the aft 01 deck handrail. SonarWiz 6 (version 6.05.001) seismic acquisition software was used to control the Geo-Star FSSB topside unit, digitally log three trace data (envelope, real, and imaginary) 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 1 - 2 second (ms) shot rates, a 40-ms pulse length, and a 1 to 6 kHz frequency sweep. Traces were recorded with a 46-microsecond sample interval over lengths between approximately 800 and 1600 ms. Process_Step: Process_Description: PROCESS STEP 1: SIOSEIS (version 2018.1.2), Shearwater Reveal (version 4.1), and python were used to process SEG-Y data and extract navigation data. The processing flows and scripts used are summarized below and in the following processing steps. 1) The SIOSEIS script sio_renum read the raw SEG-Y files, extracted the envelope-detected trace, renumbered shots starting from one, and wrote 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 siothresh_pltwbt was used to predict water-bottom times from the envelope SEG-Y traces in each file and write the predicted two-way travel times for the seafloor to a '*.wbt.csv' file. 3) The Shearwater Reveal flow read_segy called the following modules: SegyTapeRead read the traces. HeaderMath and UTMLatLong converted the navigation reference point lat/lon positions from seconds of arc to decimal degrees, projected them to UTM Zone 18N WGS 84 meters, and wrote each to new header words (NRP_LAT, NRP_LON, NRP_X, and NRP_Y). DBWrite wrote the UTM positions for each shot to an internal Reveal database table '*.shots.db'. Finally, Output wrote the traces to a new file '*.seis' in the internal Reveal format. 4) Each Reveal '*.seis' file was opened in the trace viewer, and the corresponding 'wbt.csv' was chosen for overlay on the seismic traces so that the SIOSEIS seafloor picks could be evaluated and adjusted where needed using the Reveal line digitizing tool. New '*.wbtedit.csv' files were saved for each line with corrected picks. In addition, a new Reveal table '*.tfd.tbl' was created to contain estimated two-way travel time towfish depths for each line, which were digitized along the reflection of the outgoing pulse off of the sea surface. For Line-0006 and Line-0007 no seafloor reflection was present due to a 100-ms recording delay applied during acquisition, so a static towfish depth two-way travel time estimate of 16 ms was used instead. 5) The python script swellfilter512i read each '*.wbtedit.csv' file into a numpy array, interpolated picks to the entire range of shots (if needed), and passed the picks through the scipy.ndimage.median_filter algorithm (specifying a window length of 17 and nearest mode) in order to minimize the effects of sea surface heave on the seafloor picks. The median filtered curve was subtracted from the original edited seafloor curve to produce an output series of time shifts approximating the residual heave to be applied by shot to the seismic traces for heave removal. The final swell filtered seafloor picks and static shift values were output to new '*.wbtsfsh.csv' files. 6) The Reveal flow layback_shift called the following modules: Input read the '*.seis' file and sorted the traces to FFID. The custom Python module ShotlineLayback (developed by Nathan Miller of USGS-WHCMSC) defined the horizontal offset between the GPS antenna and the SB-512i transducer (approximately 60 m astern), which was calculated via Pythagorean geometry per file; where the layback astern from the a-frame block is given by the square root of ((average towfish depth (between 10 and 19 m) + measured vertical offset between the a-frame block and water line (7.5 m))^2 + (the tow wire out beyond the block (48 m))^2); and the total layback is provided by adding the offset from the GPS antenna to the a-frame block (16.15 m). The algorithm interpolated a sail line from the navigation reference point positions (NRP_X and NRP_Y), then computed layback positions for the SB-512i shots by translating them back along the sail line by the total offset, and wrote the calculated layback positions to new header words (SRC_X, SRC_Y, REC_X, REC_Y). UTMLatLong converted the layback positions from UTM Zone 18N WGS 84 meters to decimal degrees and wrote each to new header words (NRP_LAT, NRP_LON, SRC_LAT, SRC_LON, REC_LAT, and REC_LON). HeaderMath converted Lat/Lon values from decimal degrees to seconds of arc with a scalar of 100. DBMerge transferred the swell filtered seafloor picks and static shifts stored in '*.wbtsfsh.csv' files to new header words SWFSF and SWFSHIFT, respectively. Table2Header transferred towfish depth two-way travel times stored in '*.tfd.tbl'to the new header word TFDEPTH. ApplyStatic shifted traces first by the inverse of header word SWSHIFT to apply the calculated heave removal static corrections, then by the header word TFDEPTH to apply the towfish depth static corrections. HeaderMath set header words for navigation coordinate units (geographic seconds of arc with scalar), time basis code (UTC), and chirp sweep characteristics (start/end frequencies and length). Output wrote the processed traces to a new SEG-Y files in which the trace header words SRC_X, SRC_Y, REC_X, and REC_Y represent the calculated layback coordinates. DBWrite wrote new CSV text files for each line containing the layback X and Y coordinates (UTM18N m), layback Lat/Lon coordinates (WGS84 dd), shot, year, day, hour, minute, second, navigation reference point X and Y coordinates (UTM18N m), and navigation reference point Lat/Lon coordinates (WGS84 dd). The output SEG-Y files are included in the archive '2017-002-FA_SB512i_SegyData.zip'. 7) The python script 512ilbtoSQL imported the pre-layback and layback navigation, shot, year, day, and UTC time data from CSV files into a SpatiaLite (version 4.3.0) enabled SQLite (version 3.26.0) database, creating two tables containing point geometries. The first contained records for all of the input shots with unique navigation coordinates, and the second maintained records for the first and last shots, and shots at multiples of 100. A 100-shot interval was chosen because it corresponds to the annotation and tick interval provided along the top of the seismic-reflection profile images. End shots and shots at multiples of 100 may not have unique navigation coordinates. The resulting database columns for each table consist of East, North (layback UTM18N m), Lon, Lat (WGS84 dd), LineName, ImageName, Shot, Year, JD_UTC (DDD:HH:MM:SS), SurveyID, VehicleID, DeviceID, East_o, North_o (UTM18N m), Lon_o, and Lat_o (WGS84 dd). A third table was created to contain trackline geometries generated from the unique navigation point geometries for each line (sorted by LineName and Shot), and the line length in kilometers was calculated. The resulting database columns of the line geometry table consist of LineName, ImageName, Shot_init, Shot_end, Year, JDUTC_init, JDUTC_end, SurveyID, VehicleID, DeviceID, and Length_km. These process steps and all subsequent process steps were conducted by the same person - Wayne Baldwin. Process_Date: 201909 Process_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 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: PROCESS STEP 2: The SB-512i 100 shot and trackline features were added (Add Data) into ArcMap (version 10.7) from the SQLite database, then exported (Right click on database feature class > Data > Export Data) to the new Esri polyline shapefiles '2017-002-FA_SB512i_sht100.shp' and '2017-002-FA_SB512iTracklines.shp', respectively. Process_Date: 201909 Process_Step: Process_Description: PROCESS STEP 3: The Seismic Unix script Plot512i created variable density postscript plots of the seismic profiles showing two-way travel time (seconds) along the y-axis (left margin) and shots along profile (labeled at 100 shot intervals) on the x-axis (along top of profile). The postscript images were converted to 200 dpi portable network graphic (PNG) images using ImageMagick (version 6.9.9-40). Process_Date: 201909 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_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.000001 Longitude_Resolution: 0.000001 Geographic_Coordinate_Units: decimal degrees Geodetic_Model: Horizontal_Datum_Name: WGS 1984 Ellipsoid_Name: WGS 84 Semi-major_Axis: 6378137.0 Denominator_of_Flattening_Ratio: 298.257224 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: 2017-002-FA_SB512iTracklines.shp Entity_Type_Definition: SB-512i Trackline shapefile for survey 2017-002-FA (51 polyline features). Entity_Type_Definition_Source: U.S. Geological Survey Attribute: Attribute_Label: FID Attribute_Definition: Internal feature number. Attribute_Definition_Source: Esri Attribute_Domain_Values: Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated. Attribute: Attribute_Label: Shape Attribute_Definition: Feature geometry. Attribute_Definition_Source: Esri Attribute_Domain_Values: Unrepresentable_Domain: Coordinates defining the features. Attribute: Attribute_Label: LineName Attribute_Definition: Name of the trackline along which seismic-reflection data were collected in the format: Line-FileNumber (i.e.'Line-0004'). Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: ImageName Attribute_Definition: PNG image name of seismic-reflection profile corresponding to survey line. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: Shot_init Attribute_Definition: Shot number at the start of the survey line. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1 Range_Domain_Maximum: 1 Attribute_Units_of_Measure: shot Attribute_Measurement_Resolution: 1 Attribute: Attribute_Label: Shot_end Attribute_Definition: Shot number at the end of the survey line. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 468 Range_Domain_Maximum: 7287 Attribute_Units_of_Measure: shot Attribute_Measurement_Resolution: 1 Attribute: Attribute_Label: Year Attribute_Definition: Calendar year the data were collected Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: JDUTC_init Attribute_Definition: Julian day and UTC time at the start of the survey line in the format: JD:HH:MM:SS; Julian day is the integer number (although recorded here in text string format) representing the interval of time in days since January 1 of the year of collection. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: JDUTC_end Attribute_Definition: Julian day and UTC time at the end of the survey line in the format: JD:HH:MM:SS; Julian day is the integer number (although recorded here in text string format) representing the interval of time in days since January 1 of the year of collection. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: SurveyID Attribute_Definition: WHCMSC field activity identifier (e.g. "2017-002-FA" where 2017 is the survey year, 002 is survey number of that year, and FA is Field Activity). Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: VehicleID Attribute_Definition: Survey vessel name. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: DeviceID Attribute_Definition: Sonar device used to collect seismic-reflection data. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: Length_km Attribute_Definition: Length of seismic-reflection data line in kilometers (UTM Zone 18N, WGS 84) calculated in the SQLite database. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.92 Range_Domain_Maximum: 16.66 Attribute_Units_of_Measure: kilometers Attribute_Measurement_Resolution: 0.01 Detailed_Description: Entity_Type: Entity_Type_Label: 2017-002-FA_512i_sht100.shp Entity_Type_Definition: SB512i 100-interval shot point shapefile for survey 2017-002-FA (1068 point features). Entity_Type_Definition_Source: U.S. Geological Survey Attribute: Attribute_Label: FID Attribute_Definition: Internal feature number. Attribute_Definition_Source: Esri Attribute_Domain_Values: Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated. Attribute: Attribute_Label: Shape Attribute_Definition: Feature geometry. Attribute_Definition_Source: Esri Attribute_Domain_Values: Unrepresentable_Domain: Coordinates defining the features. Attribute: Attribute_Label: East Attribute_Definition: Easting coordinate in UTM Zone 18 N meters, WGS 84 Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 512811.03 Range_Domain_Maximum: 575403.01 Attribute_Units_of_Measure: meters Attribute_Measurement_Resolution: .01 Attribute: Attribute_Label: North Attribute_Definition: Northing coordinate in UTM Zone 18 N meters, WGS 84 Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 3929839.55 Range_Domain_Maximum: 4155008.85 Attribute_Units_of_Measure: meters Attribute_Measurement_Resolution: .01 Attribute: Attribute_Label: Lon Attribute_Definition: Longitude coordinate in decimal degrees, WGS 84 Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -74.858706 Range_Domain_Maximum: -74.146661 Attribute_Units_of_Measure: degrees Attribute_Measurement_Resolution: 1E-06 Attribute: Attribute_Label: Lat Attribute_Definition: Latitude coordinate in decimal degrees, WGS 84 Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 35.512023 Range_Domain_Maximum: 37.540206 Attribute_Units_of_Measure: degrees Attribute_Measurement_Resolution: 1E-06 Attribute: Attribute_Label: LineName Attribute_Definition: Name of the trackline along which seismic-reflection data were collected in the format: Line-FileNumber (i.e.'Line-0004'). Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: ImageName Attribute_Definition: PNG image name of seismic-reflection profile corresponding to survey line. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: Shot Attribute_Definition: Shot number (values are first, last, and every 100 shot between). Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1 Range_Domain_Maximum: 7287 Attribute_Units_of_Measure: shot Attribute_Measurement_Resolution: 1 Attribute: Attribute_Label: Year Attribute_Definition: Year the data were collected YYYY. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: JD_UTC Attribute_Definition: Julian day and UTC time for first, last, and every 100 shot point between of the survey line in the format: JD:HH:MM:SS; Julian day is the integer number (although recorded here in text string format) representing the interval of time in days since January 1 of the year of collection. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: SurveyID Attribute_Definition: WHCMSC field activity identifier (e.g. "2017-002-FA" where 2017 is the survey year, 002 is survey number of that year, and FA is Field Activity). Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: VehicleID Attribute_Definition: Survey vessel name. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: DeviceID Attribute_Definition: Sonar device used to collect seismic-reflection data. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set Attribute: Attribute_Label: East_o Attribute_Definition: pre-layback calculation Easting coordinate in UTM Zone 18 meters, WGS84. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 512825.01 Range_Domain_Maximum: 575411.75 Attribute_Units_of_Measure: meters Attribute_Measurement_Resolution: .01 Attribute: Attribute_Label: North_o Attribute_Definition: pre-layback calculation Northing coordinate in UTM Zone 18 meters, WGS84. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 3929789.81 Range_Domain_Maximum: 4155004.57 Attribute_Units_of_Measure: meters Attribute_Measurement_Resolution: .01 Attribute: Attribute_Label: Lon_o Attribute_Definition: pre-layback calculation Longitude coordinate in decimal degrees, WGS 84 Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -74.858556 Range_Domain_Maximum: -74.146617 Attribute_Units_of_Measure: degrees Attribute_Measurement_Resolution: 1E-06 Attribute: Attribute_Label: Lat_o Attribute_Definition: pre-layback calculation Latitude coordinate in decimal degrees, WGS 84 Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 35.511575 Range_Domain_Maximum: 37.540164 Attribute_Units_of_Measure: degrees Attribute_Measurement_Resolution: 1E-06 Detailed_Description: Entity_Type: Entity_Type_Label: 2017-002-FA_512i_shtnav.csv Entity_Type_Definition: SB512i shot point comma separated values file for survey 2017-002-FA (99549 point features). Entity_Type_Definition_Source: U.S. Geological Survey Detailed_Description: Entity_Type: Entity_Type_Label: 2017-002-FA_512i_Images Entity_Type_Definition: Portable network graphic images of processed SB512i profiles for survey 2017-002-FA (51 PNG images). Entity_Type_Definition_Source: U.S. Geological Survey Detailed_Description: Entity_Type: Entity_Type_Label: 2017-002-FA_512i_SegyData Entity_Type_Definition: SEG-Y format files of processed SB512i profiles for survey 2017-002-FA (51 SEG-Y files). Entity_Type_Definition_Source: U.S. Geological Survey Overview_Description: Entity_and_Attribute_Overview: The column headings and range domain values in '2017-002-FA_SB512i_shtnav.csv' match those in '2017-002-FA_SB512i_sht100.shp'. The PNG seismic reflection images can be hyperlinked to their corresponding trackline or shotpoint locations in ArcGIS using the shapefiles '2017-002-FA_SB512iTracklines.shp' or '2017-002-FA_SB512i_sht100.shp', respectively. The fist, last, and multiple of 100 shot features in '2017-002-FA_SB512i_sht100.shp' correspond to the x-axis ticks on the PNG images, which show two-way travel time (seconds) on the y-axis and distance along profile (annotation at 100 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: Denver 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 Contact_Electronic_Mail_Address: sciencebase@usgs.gov Resource_Description: USGS data release of EdgeTech SB512i chirp seismic-reflection data collected along the U.S. Atlantic continental shelf break and upper slope between Accomac and Keller Canyons during USGS field activity 2017-002-FA: includes '2017-002-FA_SB512i_sht100.shp' containing the first, last and 100-interval shotpoint locations, '2017-002-FA_SB512i_shtnav.csv' containing unique shot point locations, '2017-002-FA_SB512iTracklines.shp' containing trackline features, '2017-002-FA_SB512i_Images.zip' containing 51 PNG images named according to line convention, '2017-002-FA_SB512i_SegyData.zip' containing 51 SEG-Y files of the processed traces, the browse graphic 2017-002-FA_SB512i_browse.jpg, and Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata file '2017-002-FA_SB512i_meta.xml'. These datasets can be downloaded individually (see the Digital Transfer Option section). 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: Shapefile Format_Version_Number: ArcMap 10.7.1 Format_Specification: Shapefile Format_Information_Content: Shapefile of SB512i tracklines collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center along the U.S. Atlantic continental shelf break and upper slope between Accomac and Keller Canyons during field activity 2017-002-FA and the associated metadata. File_Decompression_Technique: none Transfer_Size: 1.6 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/item/5e1e318fe4b0ecf25c610daf Network_Resource_Name: https://doi.org/10.5066/P9Y1MSTN Access_Instructions: The first link is to the page containing the data and the second is to the publication landing page. The data page (first link) may have additional data access options, including web services. Digital_Form: Digital_Transfer_Information: Format_Name: Shapefile Format_Version_Number: ArcMap 10.7.1 Format_Specification: Shapefile Format_Information_Content: Shapefile of SB512i shotpoints collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center along the U.S. Atlantic continental shelf break and upper slope between Accomac and Keller Canyons during field activity 2017-002-FA and the associated metadata. File_Decompression_Technique: none Transfer_Size: 1.8 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/item/5e1e318fe4b0ecf25c610daf Network_Resource_Name: https://doi.org/10.5066/P9Y1MSTN Access_Instructions: The first link is to the page containing the data and the second is to the publication landing page. The data page (first link) may have additional data access options, including web services. Digital_Form: Digital_Transfer_Information: Format_Name: CSV Format_Version_Number: none Format_Specification: Comma-Separated Values (CSV) Format_Information_Content: CSV file of SB512i unique shotpoints collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center along the U.S. Atlantic continental shelf break and upper slope between Accomac and Keller Canyons during field activity 2017-002-FA and the associated metadata. File_Decompression_Technique: none Transfer_Size: 16.7 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/item/5e1e318fe4b0ecf25c610daf Network_Resource_Name: https://doi.org/10.5066/P9Y1MSTN Access_Instructions: The first link is to the page containing the data and the second is to the publication landing page. The data page (first link) may have additional data access options, including web services. Digital_Form: Digital_Transfer_Information: Format_Name: PNG Format_Version_Number: ImageMagick (version 6.9.9-40) Format_Specification: Portable Network Graphic (PNG) Format_Information_Content: Zip compressed folder containing SB512i seismic reflection profile images collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center along the U.S. Atlantic continental shelf break and upper slope between Accomac and Keller Canyons during field activity 2017-002-FA and the associated metadata. File_Decompression_Technique: any zip utility Transfer_Size: 165 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/item/5e1e318fe4b0ecf25c610daf Network_Resource_Name: https://doi.org/10.5066/P9Y1MSTN Access_Instructions: The first link is to the page containing the data and the second is to the publication landing page. The data page (first link) may have additional data access options, including web services. Digital_Form: Digital_Transfer_Information: Format_Name: SEG-Y Format_Version_Number: SEG-Y Rev. 1 Format_Specification: SEG-Y Format_Information_Content: Zip compressed folder containing processed SB512i seismic reflection trace data collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center along the U.S. Atlantic continental shelf break and upper slope between Accomac and Keller Canyons during field activity 2017-002-FA and the associated metadata. File_Decompression_Technique: any zip utility Transfer_Size: 6740 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/item/5e1e318fe4b0ecf25c610daf Network_Resource_Name: https://doi.org/10.5066/P9Y1MSTN Access_Instructions: The first link is to the page containing the data and the second is to the publication landing page. The data page (first link) may have additional data access options, including web services. Fees: none Technical_Prerequisites: To utilize these data, the user must have software capable of reading shapefiles, CSV files, PNG images, and/or SEG-Y seismic trace files. 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 Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Time_Convention: local time