In July of 2000, the U.S. Geological Survey (USGS), in cooperation with the Florida Geological Survey (FGS), conducted a geophysical survey of the Atlantic Ocean offshore Florida's east coast from Brevard County to northern Martin County. This report serves as an archive of unprocessed digital boomer seismic reflection data, trackline maps, navigation files, GIS information, digital and handwritten Field Activity Collection System (FACS) logs, and Federal Geographic Data Committee (FGDC) metadata. A filtered and gained digital image of each seismic profile is also provided.
The archived trace data are in standard Society of Exploration Geophysicists (SEG) SEG-Y format (Barry and others, 1975) and may be downloaded and processed with commercial or public domain software such as Seismic Unix (SU). Examples of SU processing scripts and (USGS) software for viewing SEG-Y files (Zihlman, 1992) are also provided.
Purpose:
The data archived here were collected under a cooperative agreement between the Florida Geological Survey and the USGS.
Supplemental_Information:
The USGS St. Petersburg Coastal and Marine Science Center in Florida, assigns a unique identifier to each cruise or field activity. For example, 00FGS01 tells us the data were collected in 2000 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 boomer plate is an acoustic energy source that consists of capacitors charged to a high voltage and discharged through a transducer in the water. The transducer is towed on a sled at the sea surface and when discharged emits a short acoustic pulse, or shot, that propagates through the water and sediment column. The acoustic energy is reflected at density boundaries (such as the seafloor or sediment layers beneath the seafloor), detected by the receiver, and recorded by a PC-based seismic acquisition system. This process is repeated at timed intervals (for example, 1 second) and recorded for specific intervals of time (for example, 200 milliseconds). In this way, a 2D vertical image of the shallow geologic structure beneath the ship track is produced.
An Applied Acoustic Engineering CSP 300 power supply provided 100 joules per shot. Reflected energy was received by an Innovative Transducers, Inc. (ITI) ST-5 10-channel streamer and recorded by Triton Elics International, Inc. (TEI) Delph Seismic acquisition software. The streamer contains 10 hydrophones evenly spaced every 2 feet. Only data received by elements 4-8 were summed. Refer to the handwritten FACS overview log included in this archive for a diagram of the acquisition geometry. The sample frequency of the data is 8-12 kilohertz. Record length for all tracklines is 200 milliseconds. The shot rate was every 1 second. Shot spacing for each line is about 2.5 meters.
The unprocessed seismic data are stored in SEG-Y, 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. Additional recording parameters for each trace file can also be found in the .PAR file associated with each .TRA file. However, the .PAR and .PLN files included here are only needed to process or display the data with TEI Delph Seismic software. Also provided are example Seismic Unix scripts that allow the user to extract navigation fixes from the SEG-Y headers, along with a fix for every 500 shots, and produce a filtered and gained GIF image of each profile. The navigation information was recorded in two locations in the original SEG-Y headers. The navigation in the defined fields is only accurate to 1 second of arc or approximately 31 meters. The navigation stored in the undefined fields and used here to produce the trackline maps and navigation files and is accurate to the degree of the GPS receiver or 3-5 meters. The navigation files provided here were extracted from the undefined fields using Delph Seismic software.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20000714
Ending_Date: 20000722
Currentness_Reference: Data collection interval
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -80.494468
East_Bounding_Coordinate: -79.999170
North_Bounding_Coordinate: 28.064175
South_Bounding_Coordinate: 27.185378
Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: marine seismic reflection
Theme_Keyword: boomer
Theme_Keyword: SEG-Y
Theme_Keyword: Florida Geological Survey
Theme_Keyword: 00FGS01
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: Atlantic Ocean
Place_Keyword: Florida
Place_Keyword: Brevard County
Place_Keyword: St. Lucie County
Place_Keyword: Martin County
Place_Keyword: Indian River County
Access_Constraints: None. These data are held in the public domain.
Use_Constraints:
The U.S. Geological Survey and Florida Geological Survey request to be acknowledged as originators of the data in future products or derivative research.
Trackline map of digital boomer seismic reflection data collected during USGS Cruise 00FGS01. This map was created at a scale of 1:450,000. Refer to the Lineage section below for the trackline map creation process.
Trackline map of digital boomer seismic reflection data collected in Area A (refer to Area A of the full survey area map) during USGS Cruise 00FGS01. This map was created at a scale of 1:215,000. Refer to the Lineage section below for the trackline map creation process.
Trackline map of digital boomer seismic reflection data collected in Area B (refer to Area B of the full survey area map) during USGS Cruise 00FGS01. This map was created at a scale of 1:215,000. Refer to the Lineage section below for the trackline map creation process.
Browse_Graphic_File_Type: JPEG
Data_Set_Credit:
Funding and (or) support for this study was provided by the USGS Coastal and Marine Geology Program and the Florida Geological Survey. We would like to thank the Captain and Crew of the FGS R/V Geoquest and Henry Fredenburg, formerly with the FGS, for their assistance in data collection.
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
The validity or accuracy of marine seismic reflection 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 data set is from one field activity with consistent instrument calibrations.
Completeness_Report:
These data are collected along tracklines (2D) and are therefore inherently incomplete. Geologic details between lines must be inferred. Of a total record length of 200 milliseconds, only the upper 100 milliseconds of each profile are displayed because little useful information was observed deeper in the sections. No digital data were collected for line sl6. However, line sl6r is a second attempt to collect digital data for this line. Digital data and 500-shot-interval location navigation are not available for the last 1,161 shots of line sl26 due to equipment malfunction. For record keeping purposes, so even numbered profiles were recorded offshore of Brevard County (lines b49-b63); no odd numbered profiles were recorded offshore of St. Lucie and Martin Counties (lines s62-s636) and no odd numbered profiles were recorded offshore of Indian River and St. Lucie Counties (line ir32-ir32-ir46).
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
As the seismic reflection data were acquired, the position of the vessel was continuously determined by a Trimble Centurion GPS receiver, which is accurate within 3-5 meters. Positions were recorded and written to the trace headers in latitude and longitude coordinates about every 1 seconds. The navigation information was recorded in two locations in the original SEG-Y headers. The navigation in the defined fields is only accurate to 1 second of arc or approximately 31 meters. The navigation stored in the undefined fields and used here to produce the trackline maps and navigation files and is accurate to the degree of the GPS receiver or 3-5 meters. The navigation files provided here were extracted from the undefined fields using Delph Seismic provided software. The navigation data have not been corrected to reflect the unknown offset between the shotpoint and GPS antenna.
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. A 10-milliseconds deep-water delay appears on lines b57-b63 and sl2-sl28.
Lineage:
Process_Step:
Process_Description:
Boomer processing: The SEG-Y data were processed with Seismic Unix software to produce the GIF seismic profile images included in this report. A representative boomer processing sequence consisted of (1) running a bandpass filter of 300-500-2500-3000 Hertz, (2) applying automatic gain control, (3) displaying PostScript, and (4) converting of PostScript image to a GIF image.
Process_Date: 2004
Process_Step:
Process_Description:
Navigation processing: Navigation files were extracted from the trace headers of each line using TEI software. These files were edited to remove spurious data points and fix incorrectly recorded dates. The navigation files were then processed with PROJ.4 software http://trac.osgeo.org/proj/ to generate Zone 17 UTM. coordinates from latitude and longitude and reformat the data for use with Environmental Systems Research Institute (ESRI) ArcGIS version 8.3 software. The 500-shot-interval location files were extracted using Seismic Unix software and processed in the same manner as the navigation files.
Process_Date: 2004
Process_Step:
Process_Description:
Trackline map creation: The trackline maps provided in this archive were created using ESRI ArcGIS version 8.3 software, exported to Adobe Illustrator for further editing, and saved in JPEG format. The maps are set in geographic coordinates, NAD83. (unprojected). The USGS is the originator of all layers except for the counties layer, which is a U.S. Census Bureau data set, and the highways layer, which is a Florida Department of Transportation Statistics data set.
Process_Date: 2004
Process_Step:
Process_Description:
Archive preparation: In addition to the process steps described above, the following steps were taken to produce this archive: handwritten FACS logs were scanned and saved as PDF files, digital FACS logs were created using the handwritten 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.
Process_Date: 2004
Spatial_Data_Organization_Information:
Indirect_Spatial_Reference:
Horizontal X and Y locations (latitude and longitude and Zone 17 UTM. coordinates) for each shot are provided in ASCII position files, along with the date and time (Greenwich Mean Time) the shot was recorded.
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: 0.0000027
Longitude_Resolution: 0.0000027
Geographic_Coordinate_Units: decimal degrees
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
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 716 kilobytes to 26.1 megabytes.
Entity_and_Attribute_Detail_Citation:
Barry, K.M., Cavers, D.A., and Kneale, C.W., 1975, Recommended standards for digital tape formats: Geophysics, v. 40, n. 2, p. 344-352. Also available on-line at http://www.seg.org/publications/tech-stand.
Entity_and_Attribute_Detail_Citation:
Cohen, J.K., and Stockwell, J.W., Jr., 2005, CWP/SU: Seismic Unix Release 39: A free package for seismic research and processing: Golden, CO, Center for Wave Phenomena, Colorado School of Mines. Available on-line at http://www.cwp.mines.edu/cwpcodes/.
Entity_and_Attribute_Detail_Citation:
Zihlman, F.N., 1992, DUMPSEGY V1.0: A program to examine the contents of SEG-Y disk-image seismic data: U.S. Geological Survey Open-File Report 92-590, 28 p.
Entity_and_Attribute_Overview:
Disc Image Credit: Descloitres, J., MODIS Rapid Response Team at the NASA Goddard Space Flight Center, 2003, Florida.A2003044.jpg. Available online at http://visibleearth.nasa.gov/view_rec.php?id=5049
Entity_and_Attribute_Overview:
Graphic image file: Profiles are available as GIF images that range in size from 77 to 855 kilobytes. Trackline maps, which range in size from 79 to 100 kilobytes, are JPEG images that contain links to the seismic profile GIF images.
Entity_and_Attribute_Overview:
Navigation file: Navigation files are available as ASCII text files. Raw navigation files range in size from 18 to 585 kilobytes. The edited navigation file is 13.5 megabytes and the edited 500-shot-interval location file is 23.4 kilobytes.
Entity_and_Attribute_Overview:
GIS file: The ArcGIS version 8.3 project used to create the trackline maps is provided as a .zip file composed of map documents, shapefiles, and metadata. The map documents range in size from 454 to 525 kilobytes, and the shapefiles range in size from 6 kilobytes to 29 megabytes.
Contact_Instructions: All of this report is available on-line.
Resource_Description: U.S. Geological Survey Data Series 496
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
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: 744.4 megabytes
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 using ESRI ArcGIS version 8.3 software. The shapefiles provided may also be viewed using other versions of ArcView, ArcGIS, or public domain software ArcExplorer http://www.ESRI.com/software/arcexplorer/.
File_Decompression_Technique: unzip
Transfer_Size: 25.1 megabytes
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: DVD/software/arc/arc.zip
Fees: Prices vary.
Ordering_Instructions: Refer to the Distributor Contact Information section above.
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/
Metadata_Reference_Information:
Metadata_Date: 20091202
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Matthew Streubert
Contact_Organization: Jacobs Technology Inc.
Contact_Position: Assistant Data Analyst/Modeling
Contact_Address:
Address_Type: mailing and physical
Address: U.S. Geological Survey, 600 4th Street South
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