In July of 2005, the U.S. Geological Survey (USGS), in cooperation with the Florida Geological Survey (FGS), conducted a geophysical survey of the Atlantic Ocean offshore of Florida's east coast from Flagler Beach to Daytona Beach. This report serves as an archive of unprocessed digital boomer subbottom data, trackline maps, navigation files, GIS information, and formal FGDC metadata. Filtered and gained digital images of the seismic profiles are also provided. The archived trace data are in standard Society of Exploration Geophysicists (SEG) SEG Y revision 0 format (Barry and others, 1975) and may be downloaded and processed with commercial or public domain software such as Seismic Unix (SU). Example SU processing scripts and USGS software for viewing the SEG Y files (Zihlman, 1992) are also provided.
The data archived here were collected under a cooperative agreement between the Florida Geological Survey and the USGS.
Supplemental_Information:
The USGS Saint Petersburg Coastal and Marine Science Center (SPCMSC) - St. Petersburg, FL, assigns a unique identifier to each cruise or field activity. For example, 05FGS01 tells us the data were collected in 2005 for the Florida Geological Survey (FGS) cooperative agreement and the data were collected during the first field activity for that project in that calendar year. Refer to <http://walrus.wr.usgs.gov/infobank/programs/html/definition/activity.html> for a detailed description of the method used to assign the cruise ID. The naming convention used for each subbottom line is as follows: yye##a, where 'yy' are the last two digits of the year in which the data were collected, 'e' is a 1-letter abbreviation for the equipment type (for example, b for boomer), '##' is a 2-digit number representing a specific track, and 'a' is a letter representing the section of a line if recording was prematurely terminated or rerun for quality or acquisition problems.
The boomer subbottom processing system consists of an acoustic energy source that is made up of capacitors charged to a high voltage and discharged through a transducer in the water. The transducer is towed on a sled floating on the water surface and when discharged emits a short acoustic pulse, or shot, that propagates through the water column and shallow stratigraphy below. The acoustic energy is reflected at density boundaries (such as the seafloor or sediment layers beneath the seafloor), detected by the receiver (hydrophone streamer), and recorded by a PC-based seismic acquisition system. This process is repeated at timed intervals (for example, 0.5 s) and recorded for specific intervals of time (for example, 100 ms). In this way, a 2-D vertical image of the shallow geologic structure beneath the ship track is produced.
An Applied Acoustic Engineering CSP 300 provided 100 Joules of energy per shot. Reflected energy was received by a Benthos Mesh 15-m-long streamer and recorded by Triton Elics International, Inc. (TEI) Delph Seismic v. 2.7 acquisition software. The streamer contains 10 hydrophones evenly spaced every 0.305 m. The streamer was positioned directly behind the research vessel (parallel to the boomer sled), with a lateral separation of approximately 7 m. Refer to figure 1 included with this archive for a diagram of the acquisition geometry. The sample frequency of the data was 24 kHz, and record length was 100 ms. The shot spacing was highly variable; however, based on survey speeds of 3 knots and a shot rate of every 0.5 s, shot spacing was about 0.514 m.
The unprocessed seismic data are stored in SEG Y rev. 0, integer, Motorola format, which is a standard digital format that can be read and manipulated by most seismic processing software packages (Barry and others, 1975). The SEG Y formatted trace files have a .tra extension.
The printable profiles provided here are GIF images that were filtered and gained using Seismic Unix software. The processed SEG Y data were exported to Chesapeake Technology, Inc. (CTI) SonarWeb software to produce a geospatially interactive version of the profile that allows the user to obtain a geographic location and depth from the profile for a given cursor position on the profile; this information is displayed in the status bar of the browser. Please note that clicking on the profile image switches it to "Expanded View" (a compressed image of the entire line) and cursor tracking is not available in this mode. NOTE: The only supported Web browsers that properly display all features of the geospatial profiles are Internet Explorer 6 or greater for Windows and Firefox 3.6 or greater for all platforms. PC Instructions: For both browsers, the status bar and JavaScript must be enabled. If using Internet Explorer 6 or greater, you must disable scripts/Active X controls. To do this, right click the information bar (found at the top of the page), left click "Allow Blocked Content...", and then select "Yes". Use of other browsers may result in spurious or no information given in the status window. Firefox may be downloaded at <http://www.mozilla.org/products/firefox>. Macintosh Instructions (Firefox Only): From the Menu Bar go to Preferences > Content (tab) > Checkmark "Enable JavaScript"> Click Advanced... > Checkmark "Change Status Bar Text". Verify that the status bar is enabled by selecting View from the Menu Bar and looking for a checkmark next to "Status Bar"; if the check is missing, highlight and select the text to activate the bar.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20050717
Ending_Date: 20050725
Currentness_Reference: Data collection interval
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -81.151788
East_Bounding_Coordinate: -80.832257
North_Bounding_Coordinate: 29.650501
South_Bounding_Coordinate: 29.183042
Keywords:
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: geoscientificinformation
Theme_Keyword: oceans
Theme:
Theme_Keyword_Thesaurus: General
Theme_Keyword: Geology
Theme_Keyword: Coastal information
Theme_Keyword: Marine
Theme_Keyword: Subbottom profile
Theme_Keyword: Seismic reflection
Theme_Keyword: Boomer
Theme_Keyword: Society of Exploration Geophysicists
Access_Constraints: None. These data are held in the public domain.
Use_Constraints:
The U.S. Geological Survey and Florida Geological Survey (FGS) request to be acknowledged as originators of the data in future products or derivative research.
Location map of digital boomer subbottom data collected during USGS Field Activity 05FGS01. This map was created at a scale of 1:321,000. Refer to the Lineage section below for the trackline map creation process.
Directory containing printable images of all subbottom profiles.
Browse_Graphic_File_Type: GIF
Data_Set_Credit:
Funding and (or) support for this study was provided by the USGS Coastal and Marine Geology Program and FGS. This document was improved by the reviews of Lisa Robinson (USGS) and Marilyn Montgomery (Jacobs Technology Inc.) of the USGS - St. Petersburg, FL.
Disc Image Credit: Schmaltz, Jeff, MODIS Rapid Response Team at the NASA Goddard Space Flight Center, 2004, UnitedStates.A2004106.1855.500m.jpg. Also available on-line at <http://eoimages.gsfc.nasa.gov/ve/6886/UnitedStates.A2004106.1855.500m.jpg>
Cross_Reference:
Citation_Information:
Originator: Cohen, J.K., and Stockwell, J.W., Jr., CWP/SU
Publication_Date: 2010
Title:
Seismic Unix Release 41: A free package for seismic research and processing, Center for Wave Phenomena, Colorado School of Mines
The validity or accuracy of marine subbottom profiles 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.
Logical_Consistency_Report:
This dataset is from one field activity with consistent instrument calibrations.
Completeness_Report:
These data are collected along tracklines (2-D) and are therefore inherently incomplete. Geologic details between lines must be inferred. No data were collected for lines 05b02 and 05b19-05b23.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
As the subbottom data were acquired, the position of the vessel was continuously determined by a CSI Wireless DGPS Max receiver, which is accurate within 1 m if WAAS is available, or 3-5 m otherwise. Positions were recorded and written to the trace headers in latitude and longitude coordinates about every 1 s. The approximately 30-m offset between the Boomer shot and GPS was not accounted for during acquisition nor have the ASCII navigation files and trackline map been corrected to reflect the offset. Line navigation maps and geospatial profiles generated with CTI SonarWeb software have been corrected for the GPS offsets.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
Boomer data are relative to sea level. However, varying recorded static shifts of the data have been known to occur. Therefore, these data are not to be used for bathymetry.
Lineage:
Process_Step:
Process_Description:
Boomer processing: The SEG Y data were processed with Seismic Unix to produce GIF images of the seismic profiles included in this report. A representative boomer processing sequence consisted of (1) running a bandpass filter of 300-500-2500-3000 Hz, (2) applying automatic gain control, (3) displaying PostScript, and (4) converting of PostScript image to a GIF image.
All the processed SEG Y data were then exported to CTI SonarWeb software to produce a geospatial version of each profile that allows the user to obtain a geographic location and depth for a given cursor position on the profile. Refer to the Supplemental Information section above for details on how to use the geospatial profiles.
Navigation processing: Shotpoint navigation, start of line, and 500-shot-interval location files were extracted using Seismic Unix software and output as ASCII text files; they were then processed with PROJ.4.7.0 (<http://trac.osgeo.org/proj/>) to generate UTM coordinates from latitude and longitude coordinates. Text files for each seismic line were concatenated into two comma-delimited text files (for use with ESRI software), one containing unique shotpoint positions (05fgs01.txt) and another containing the 500-shot-interval locations (s05fgs01.txt); both can be viewed within the nav folder.
All concatenated, comma-delimited text files were imported into ArcGIS and saved as either a point or polyline file in the ESRI shapefile format.
Trackline map creation: The trackline map was created using ESRI ArcGIS 10 software. The processed navigation file, 05fgs01.txt, was imported into ArcMap 10 and processed using the Points to Lines ArcScript (D. Rathert, <http://arcscripts.esri.com/details.asp?dbid=12702>) to create a line shapefile of the cruise tracklines (05fgs01_trkln). The 500-shot-interval file s05fgs01.txt and the start of line file 05fgs01_s.txt were imported into ArcMap as point shapefiles 05fgs01_shots and 05fgs01_sol. Please refer to the shapefile metadata included in the ArcGIS map document located under the Software section of this archive for additional details. The location map was exported to Adobe Illustrator v. 14 for further editing then later converted into JPEG format by Adobe Dreamweaver v. 10 Build 4117. The map is unprojected (geographic coordinates, WGS84). The interstates layer used on the trackline map was created by ESRI. The USGS is the originator of all other layers used. A map of trackline navigation for each subbottom profile was also produced with CTI SonarWeb software. Please see the ArcGIS readme file for detailed information about the GIS files used in this report.
Data Series preparation: In addition to the process steps described above, the following steps were taken to produce this Data Series report: the handwritten (<https://pubs.usgs.gov/ds/647/logbooks/handwritten/>) cruise logs were scanned and saved as a PDF file, digital (<https://pubs.usgs.gov/ds/647/logbooks/digital/>) logs were created by A. Forde using the cruise logs and personal accounts of the crew members and saved as PDF files, and an HTML-based format was used to present the various parts of this archive.
Horizontal X and Y locations (latitude and longitude and Zone 17 UTM coordinates) for each shot are provided as ASCII text files, along with the date and time (UTC) the shot was recorded.
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: UTMX
Attribute_Definition: UTM-X coordinate (Zone 17)
Attribute_Definition_Source: Universal Transverse Mercator Geographic Coordinate System
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 485419
Range_Domain_Maximum: 516280
Attribute_Units_of_Measure: meters
Attribute:
Attribute_Label: UTMY
Attribute_Definition: UTM-Y coordinate (Zone 17)
Attribute_Definition_Source: Universal Transverse Mercator Geographic Coordinate System
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 3228278
Range_Domain_Maximum: 3280044
Attribute_Units_of_Measure: meters
Attribute:
Attribute_Label: Line
Attribute_Definition: Trackline number
Attribute_Definition_Source: U.S. Geological Survey
Attribute_Domain_Values:
Unrepresentable_Domain:
The naming convention used for each subbottom line is as follows: yye##a, where 'yy' are the last two digits of the year in which the data were collected, 'e' is a 1-letter abbreviation for the equipment type (for example, b for boomer), '##' is a 2-digit number representing a specific track, and 'a' is a letter representing the section of a line if recording was prematurely terminated or rerun for quality or acquisition problems.
Attribute:
Attribute_Label: Shot
Attribute_Definition: Shotpoint number
Attribute_Definition_Source: U.S. Geological Survey
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1
Range_Domain_Maximum: 20000
Attribute:
Attribute_Label: Lon
Attribute_Definition: Longitude (decimal degrees)
Attribute_Definition_Source: World Geodetic System 1984 Geographic Coordinate System
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -81.15062
Range_Domain_Maximum: -80.832379
Attribute_Units_of_Measure: decimal degrees
Attribute:
Attribute_Label: Lat
Attribute_Definition: Latitude (decimal degrees)
Attribute_Definition_Source: World Geodetic System 1984 Geographic Coordinate System
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 29.183103
Range_Domain_Maximum: 29.650282
Attribute_Units_of_Measure: decimal degrees
Attribute:
Attribute_Label: YEAR
Attribute_Definition: Year
Attribute_Definition_Source: U.S. Geological Survey
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 2005
Range_Domain_Maximum: 2005
Attribute:
Attribute_Label: DOY:HR:MIN:SEC
Attribute_Definition: Day of year:hour:minute:second
Attribute_Definition_Source: U.S. Geological Survey
Attribute_Domain_Values:
Unrepresentable_Domain: Day of year, hour, minute and second of data acquisition
Overview_Description:
Entity_and_Attribute_Overview:
Binary data file: Trace data are available as binary files in SEG Y format. These files have a .tra extension and range in size from 4.3 to 110 MB. These data can be found by going to <https://pubs.usgs.gov/ds/647/segy/>
Entity_and_Attribute_Overview:
Graphic image file: Printable versions of the subbottom profiles are available as GIF images, links to these images can be found on the Profiles page or by going to <https://pubs.usgs.gov/ds/647/profiles/printable/>.
Entity_and_Attribute_Overview:
Navigation file: Navigation files are available as ASCII text files. Provided are raw (unprocessed) shotpoint navigation files (05b**.txt), processed shotpoint navigation (05fgs01.txt), processed 500-shot-interval location (s05fgs01.txt), and a start of line file (05fgs01_s.txt). Fields/Attributes [FID, Shape] marked above with an asterisk (*) were created by ESRI ArcGIS and are used exclusively by the shapefiles created from the aforementioned .txt files; these fields are not included in the original navigation files. All remaining attributes listed in the above section that do not have an accompanying asterisk are found in 05fgs01.txt, s05fgs01.txt, and 05fgs01_s.txt. Raw and processed navigation data files can be found by going to <https://pubs.usgs.gov/ds/647/nav/>.
Entity_and_Attribute_Overview:
GIS file: The GIS project used to create the trackline maps is provided as a .zip file composed of ESRI map documents, shapefiles, and metadata.
Entity_and_Attribute_Detail_Citation: Information is derived from SEG Y headers.
All of this report is available online. The SEG Y files are downloadable from the Coastal and Marine Geoscience Data System (<http://cmgds.marine.usgs.gov>).
Resource_Description: U.S. Geological Survey Data Series 647
Distribution_Liability:
This DVD 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.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: SEG Y rev. 0
Format_Information_Content:
The SEG Y standard format (Barry and others, 1975) 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.
File_Decompression_Technique: None
Transfer_Size: 1.58 GB
Digital_Transfer_Option:
Offline_Option:
Offline_Media: DVD
Recording_Format: ISO 9660
Compatibility_Information: Unix, Linux, DOS, Macintosh
Digital_Form:
Digital_Transfer_Information:
Format_Name: map document, shapefile, metadata
Format_Information_Content:
The GIS project used to create the trackline maps is composed of map documents, shapefiles, and metadata. Map documents were created with ESRI ArcGIS 10 software. The shapefiles provided may also be viewed using other versions of ESRI desktop software including their free software ArcGIS Explorer (<http://www.esri.com/software/arcgis/explorer/>).
Fees: None, if obtained online; otherwise, prices vary.
Ordering_Instructions:
Publications are available from USGS Information Services, Box 25286, Federal Center, Denver, CO 80225-0046 (telephone: 1-888-ASK-USGS, e-mail: infoservices@usgs.gov).
Technical_Prerequisites:
Use of SEG Y data requires specialized seismic processing software, such as public domain software Seismic Unix (<http://www.cwp.mines.edu/cwpcodes/>).
