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ARCHIVE OF BOOMER SEISMIC REFLECTION DATA
COLLECTED DURING USGS FIELD ACTIVITIES
01ASR01, 01ASR02, 02ASR01, AND 02ASR02,
MIAMI, FLORIDA, NOVEMBER 2001 - JANUARY 2002

Karynna Calderon, Shawn V. Dadisman, Jack L. Kindinger, Dana S. Wiese, and James G. Flocks

U.S. Geological Survey, St. Petersburg, Florida, 33701

U.S. Geological Survey Open-File Report 02-408


Note: The web version of this archive does not contain the SEG-Y Trace files. These files are very large and would require extremely long download times. To obtain the complete CD-ROM archive, contact USGS Information at (888) ASK-USGS.

In November 2001, the U.S. Geological Survey, in cooperation with the South Florida Water Management District, began a four-phase geophysical study of the shallow geology and the upper Floridan and surficial aquifers in the vicinity of Miami, Florida. This study was part of the USGS CMGP project on Aquifer Storage and Recovery and Leaky Coastal Margins. These CD-ROMs serve as an archive of unprocessed digital boomer seismic reflection data, trackline navigation files, shotpoint navigation maps, observer's logbooks, GIS information, and formal Federal Geographic Data Committee (FGDC) metadata. In addition, a filtered and gained digital GIF-formatted image of each seismic profile is provided.

This CD-ROM (Compact Disc-Read Only Memory) document was produced in accordance with ISO 9660 CD-ROM standards and is readable on any computing platform that has standard CD-ROM driver software installed. Documentation on these CD-ROMs was produced using Hyper Text Markup Language (HTML) utilized by the World Wide Web (WWW) and allows the user to access the information by using a web browser (i.e. Netscape or Internet Explorer). To access the information contained on these discs, open the file 'index.htm' located at the top level of these discs using your web browser. This report also contains WWW links to USGS collaborators and other agencies. These links are only accessible if access to the internet is available while viewing the CD-ROMs.

The archived boomer seismic reflection data is in standard Society of Exploration Geophysicists (SEG) SEG-Y format (Barry et al., 1975) and may be downloaded for processing with public domain software such as Seismic Unix (SU), which can be downloaded at http://www.cwp.mines.edu/cwpcodes. Note: The web version of this archive does not contain the SEG-Y Trace files. These files are very large and would require extremely long download times. To obtain the complete CD-ROM archive, contact USGS Information at (888) ASK-USGS. Examples of SU processing scripts are provided in the boom.tar file located in the SEISUNIX subfolder of the SOFTWARE folder located at the top level of these CD-ROMs. In-house (USGS) DOS and Microsoft Windows compatible software for viewing SEG-Y headers—DUMPSEGY.EXE (Zilhman, 1992)—is provided in the USGS subfolder of the SOFTWARE folder. Processed boomer profiles, shotpoint navigation maps, and logbooks may be viewed with your web browser.


BACKGROUND

This archive consists of two-dimensional marine seismic reflection profile data collected in canals in the Miami, Florida area. This data was acquired in November and December of 2001 and January and February of 2002 using a 4.9-meter (16-foot) jonboat. These data are available in a variety of formats, including binary, ASCII, HTML, shapefiles, and GIF images. Binary data are in SEG-Y format and may be downloaded for further processing or display. Reference maps and GIF images of the profiles may be viewed with your web browser. All GIS information provided is compatible with Environmental Systems Research Institute (ESRI) software. A reconnaissance test line (02ASR02-02b02) was collected northwest of the survey area during Field Activity 02ASR02 for possible use in a future project. It is archived here for organizational purposes only.

Purpose:
Marine seismic reflection data is used to image and map sedimentary and structural features of the seafloor and subsurface. These data are useful in mapping stratigraphy and in assessing other submarine geologic characteristics and features. These data were collected as part of a larger Aquifer Storage and Recovery and Leaky Coastal Margins project done in cooperation with the South Florida Water Management District.

Supplemental Information:
Seismic reflection profiles are acquired by means of an acoustic source (usually generated electronically) and a hydrophone or hydrophone array. Both elements are typically towed in the water behind a survey vessel. The sound source emits a short acoustic pulse, which propagates through the water and sediment columns. The acoustic energy is reflected at density boundaries (such as the seafloor or sediment layers beneath the seafloor) and detected at the hydrophone. This process is repeated at intervals ranging between 100 milliseconds and 1 second depending on the source type. In this way, a two-dimensional image of the geologic structure beneath the ship track is constructed.

Seismic data were stored in SEG-Y format (Barry et al., 1975), which is a standard digital format that can be read and manipulated by most seismic-processing software packages. The SEG-Y file format includes a 3200-byte descriptive header that contains detailed information regarding the data acquisition and processing parameters. All data presented here is stored in SEG-Y, Integer, Motorola format. The SEG-Y data files are too large to fit on one CD-ROM, so they have been distributed onto two CD-ROMs, with the SEG-Y data files for Field Activities 01ASR01 and 01ASR02 on Disc 1 and the SEG-Y data files for Field Activities 02ASR01 and 02ASR02 on Disc 2. The SEG-Y formatted trace data files are located in the SEGY folder located at the top level of these CD-ROMs and have a .TRA extension. Additional recording parameters for each seismic data file can also be found in the .PAR file associated with each .TRA file. However, the .PAR files and UTM_401_1.pln file are only needed to replay the data with Triton Elics Delph Seismic software. Note: The web version of this archive does not contain the SEG-Y Trace files. These files are very large and would require extremely long download times. To obtain the complete CD-ROM archive, contact USGS Information at (888) ASK-USGS.

For Field Activity 01ASR01, the seismic source employed consisted of a boomer transducer towed on a sled at the sea surface providing 100 joules per shot. The reflected energy was received by an SN Technologies NexGen solid core streamer and recorded by PC-based Triton Elics Delph Seismic acquisition software. The streamer contains 10 hydrophones evenly spaced every 2 meters. Only data received by elements 7 and 8 were summed for line 01b01 and for line 01b02 through shot number 2,819. Afterward, only data received by elements 8 and 9 were summed. The streamer was positioned parallel to the boomer sled and laterally separated from it by approximately 3 meters. The sled was towed approximately 5 meters behind the GPS antenna. The sample frequency of the data was 12 kilohertz, and the total record length was 100 milliseconds. The fire rate was every 0.5 seconds, which resulted in a shot spacing of about 0.64 meters.

For Field Activity 01ASR02, the seismic source employed consisted of a boomer transducer towed on a sled at the sea surface providing 280 joules per shot. The reflected energy was received by an SN Technologies NexGen solid core streamer and recorded by PC-based Triton Elics Delph Seismic acquisition software. The streamer contains 10 hydrophones evenly spaced every 2 meters. Only data received by elements 8 and 9 were summed for line 01b01 through shot number 8,903.  Afterward, data received by element 10 was also summed. The streamer was positioned parallel to the boomer sled and laterally separated from it by approximately 3 meters. The sled was towed approximately 5 meters behind the GPS antenna. The sample frequency of the data was 24 kilohertz, and the total record length was 100 milliseconds. The fire rate was every 0.5 seconds, which resulted in a shot spacing of about 0.64 meters.

For Field Activity 02ASR01, the seismic source employed consisted of a boomer transducer towed on a sled at the sea surface providing 280 joules per shot. The reflected energy was received by an SN Technologies NexGen solid core streamer and recorded by PC-based Triton Elics Delph Seismic acquisition software. The streamer contains 10 hydrophones evenly spaced every 2 meters. Only data received by elements 8, 9, and 10 were summed for line 02b01 and for line 02b02 through shot number 1,748. Only data received by elements 5, 6, and 7 were summed for line 02b02 between shot numbers 1,750 and 2,828. For the rest of line 02b02 and for all other lines, only data received by elements 4, 5, and 6 were summed. The streamer was positioned parallel to the boomer sled and laterally separated from it by approximately 3 meters. The sled was towed approximately 5 meters behind the GPS antenna. The sample frequency of the data was 12 kilohertz for line 02b01 and 24 kilohertz for all other lines. The total record length was 100 milliseconds. The fire rate was every 0.5 seconds, which resulted in a shot spacing with a range of about 0.46 to 0.64 meters.

For Field Activity 02ASR02, the seismic source employed consisted of a boomer transducer towed on a sled at the sea surface providing 280 joules per shot. The reflected energy was received by an Innovative Transducer, Inc. (ITI) solid core streamer and recorded by PC-based Triton Elics Delph Seismic acquisition software. The streamer contains 10 hydrophones evenly spaced about every 0.6 meters (2 feet). However, only data received by elements 3 and 4 were summed. The streamer was positioned parallel to the boomer sled and laterally separated from it by approximately 3.5 meters. The sled was towed approximately 5.5 meters behind the GPS antenna through shot number 8,230 of line 02b01, approximately 7.5 meters behind the antenna for the rest of line 02b01, and about 6 meters behind the antenna for line 02b02. The sample frequency of the data was 24 kilohertz, and the total record length was 100 milliseconds. The fire rate was every 0.5 seconds, which resulted in a shot spacing with a range of about 0.46 to 0.64 meters.

Differential GPS navigation was fed to the acquisition system every second by a WAAS/Beacon DGPS receiver. The accuracy of this receiver is to within 5 meters. However, the data required some editing to remove spurious fixes. These edited results were used to generate the trackline maps presented here. The navigation data has not been corrected to reflect the offset between the source and the GPS antenna. Position fixes for every 500 shots and for the start of line are also provided as an aide for registering of the data after plotting. All navigation data presented in this archive is stored as flat ASCII text files in the NAV folder located at the top level of these CD-ROMs. Edited navigation files are stored in the EDITNAV subfolder of the NAV folder, unedited navigation files are stored in the RAWNAV subfolder, and 500-shot interval files are stored in the SHOTNAV subfolder.

The trackline maps provided in this archive are in geographic projection. They were created using ESRI's GIS software ArcView 3.2, exported to Adobe Illustrator for further editing, and saved as GIF images. These GIF images are viewable with your web browser and can be found in the MAPS folder located at the top level of these CD-ROMs. The arc project and shapefiles used to create the maps are available in the ARC subfolder of the SOFTWARE folder located at the top level of Disc 2. The project is compatible with ArcView 3.x (UNIX or Windows) and ArcGIS 8.1 (Windows). The shapefiles can be viewed using the public domain software ArcExplorer 2.0 (Windows) and 4.0 (Windows, UNIX, Linux), which can be downloaded from the ESRI website at http://www.esri.com/software/arcexplorer/.

Field Activity Collection System (FACS) logs are available in both html and Rich Text format. They can be found in the FACS folder located at the top level of these CD-ROMs. Scanned GIF images of the original FACS logbooks are also provided. They can be found in the LOGBOOKS folder located at the top level of these CD-ROMs.

Also included on these CD-ROMs are Seismic Unix (SU) scripts that allow the user to strip off navigation fixes from the SEG-Y headers, along with a fix for every 500 shots. The seismic data is then converted to SU format, filtered, and gained, and GIF-formatted images of the profiles are produced. These images can then be displayed using a variety of shareware programs such as ImageMagick (UNIX or Linux) or a web browser.

A reconnaissance test line (02ASR02-02b02) was collected during Field Activity 02ASR02 for possible use in a future project. It is archived here for organizational purposes only.


 

DISC CONTENTS

INDEX.HTM:  a home page for viewing this report using a WWW browser

README.RTF:  a Rich Text formatted version of this page

DISCLAIM.RTF: the USGS disclaimer for this report in Rich Text format

METADATA.RTF: formal FGDC metadata for the seismic reflection data and for the associated shotpoint navigation maps in Rich Text format

FACS Folder: contains the 01ASR01, 01ASR02, 02ASR01, and 02ASR02 subfolders, each of which contains the Field Activity Collection System logs that document the field activity overview, crew, equipment, and operations in Rich Text format

01ASR01 Subfolder

01ASR02 Subfolder

02ASR01 Subfolder

02ASR02 Subfolder

LOGBOOKS Folder: contains the 01ASR01, 01ASR02, 02ASR01, and 02ASR02 subfolders, each of which contains scanned GIF images of the observer's original handwritten FACS logbook

01ASR01 Subfolder

01ASR02 Subfolder

02ASR01 Subfolder

02ASR02 Subfolder

HTML Folder: contains all HTML documents used in this report and GIF images used by the HTML hyperlinks

MAPS Folder: contains GIF images of the trackline maps

NAV Folder: contains the EDITNAV, RAWNAV, and SHOTNAV subfolders

EDITNAV Subfolder: contains edited navigation files extracted from the SEG-Y headers in ASCII text format by Field Activity ID

RAWNAV Subfolder: contains the 01ASR01, 01ASR02, 02ASR01, and 02ASR02 subfolders, each of which contains the raw navigation for each line extracted by Delph Seismic in ASCII text format

SHOTNAV Subfolder: contains edited navigation fixes for every 500-shot interval in ASCII text format by Field Activity ID

PROFILES Folder: contains the 01ASR01, 01ASR02, 02ASR01, and 02ASR02 subfolders, each of which contains GIF images of the processed boomer seismic profiles for that Field Activity

01ASR01 Subfolder

01ASR02 Subfolder

02ASR01 Subfolder

02ASR02 Subfolder

SEGY Folder: contains the 01ASR01 and 01ASR02 subfolders on Disc 1 and the 02ASR01 and 02ASR02 subfolders on Disc 2, each of which contains unprocessed digital boomer seismic reflection data in SEG-Y format

Note: The web version of this archive does not contain the SEG-Y Trace files. These files are very large and would require extremely long download times. To obtain the complete CD-ROM archive, contact USGS Information at (888) ASK-USGS.

01ASR01 Subfolder

01ASR02 Subfolder

02ASR01 Subfolder

02ASR02 Subfolder

SOFTWARE Folder: contains the SEISUNIX and USGS subfolders on Disc 1 and the ARC, SEISUNIX, and USGS subfolders on Disc 2

ARC Subfolder: contains the arc project and associated shapefiles used to create the trackline maps and README.RTF, a file that describes the project and shapefiles

SEISUNIX Subfolder: contains boom.tar, a Linux tar file that contains example Seismic Unix scripts used to process and plot the boomer reflection data and extract shot navigation from the SEG-Y headers

USGS Subfolder: contains the DOS program DUMPSEGY.EXE used for viewing SEG-Y headers and associated reference documentation

 


DISCLAIMER

This Compact Disc-Read Only Memory (CD-ROM) publication was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

Although all data published on these CD-ROMs have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and/or the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data, software, or related materials.

 


ACKNOWLEDGEMENTS

This work was funded by the South Florida Water Management District office in Miami, Florida. We thank Chandra A. Dreher of the USGS in St. Petersburg, Florida, for her field support during data collection and Gina M. Peery of the USGS in St. Petersburg, Florida, for her assistance with the web design layout for this archive, as well as for providing examples of her formal metadata. We also thank reviewers Robert B. Halley and Charles W. Holmes of the USGS in St. Petersburg, Florida, whose comments improved this document.


REFERENCES

Barry, R.M., Cavers, D.A., and Kneale, C.W., 1975, Recommended standards for digital tape formats: Geophysics, v. 40, p. 344-352.

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 92-590.


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