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| 95LCA03 and 96LCA02 Data Archive |
1CSC, contracted by U.S. Geological Survey, St. Petersburg, FL 33701.
2U.S. Geological Survey, St. Petersburg, FL 33701.
3U.S. Geological Survey, Tampa, FL 33612.
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).
Table of Contents:Information StatementSystem RequirementsProject SummaryDisc OrganizationGetting StartedAcknowledgmentsReferences Cited |
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This DVD 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 makes 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 constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
Although all data and software published on this disc 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.
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 DVD archive, contact USGS Information Services at 1-888-ASK-USGS.
This disc is readable on any computing platform that has standard DVD driver software installed. The minimum software requirements are a web browser, Acrobat Reader, and a text editor. Warning! The only supported web browsers that properly display all features of the interactive profiles are Internet Explorer 6 for Windows and Firefox 1.5 for all platforms
In October and November of 1995 and February of 1996, the U.S. Geological Survey, in cooperation with the Southwest Florida Water Management District, conducted geophysical surveys of the Peace River in west-central Florida from east of Bartow to west of Arcadia. This report serves as an archive of unprocessed digital boomer seismic reflection data, trackline maps, navigation files, GIS files, Field Activity Collection System (FACS) logs, observers' logbooks, and formal FGDC metadata. Filtered and gained digital images of the seismic profiles are also provided. Refer to the Acronyms page for expansion of acronyms and abbreviations used in this report.
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). Example SU processing scripts and USGS software for viewing the SEG-Y files (Zihlman, 1992) are also provided.
These data were collected as part of the USGS Lakes and Coastal Aquifers (LCA) Project. The main objectives were: 1) to determine if a geologic model of the Peace River could be constructed from geophysical data collected in a shallow riverine environment, and 2) to extend those findings to a study of the hydraulic connection between the Peace River basin and the underlying aquifer systems. For further information about this study refer to Lewelling and others (1998).
The USGS Florida Integrated Science Center (FISC) - St. Petersburg assigns a unique identifier to each cruise or field activity. For example, 95LCA03 tells us the data were collected in 1995 for the Lakes and Coastal Aquifers (LCA) Project and the data were collected during the third 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 field activity 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 a receiver, and recorded by a PC-based seismic acquisition system. This process is repeated at timed intervals (e.g., 0.5 s) and recorded for specific intervals of time (e.g., 100 ms). In this way, a two-dimensional vertical image of the shallow geologic structure beneath the ship track is produced
Figure 1 displays acquisition geometry for both field activities, and table 1 is a summary of acquisition parameters. See the FACS equipment log (12 KB) for details about the acquisition equipment used. Table 2a lists trackline statistics for 95LCA03, and table 2b lists trackline statistics for 96LCA02. Scanned images of the handwritten observers' logbooks and acquisition geometry diagrams are also provided as PDF files.
The unprocessed seismic data are stored in SEG-Y format (Barry and others, 1975). For a detailed description of the data format, refer to the SEG-Y Format page. See the How To Download SEG-Y Data page for download instructions. The printable profiles provided here are GIF images that were filtered and gained using Seismic Unix software. Refer to the Software page for details about the processing and examples of the processing scripts. The processed SEG-Y data were then exported to Chesapeake Technology, Inc. (CTI) SonarWeb software to produce an interactive version of the profile that allows the user to obtain a geographic location and depth from the profile for a curser position. This information is displayed in the status bar of the browser. Warning! The only supported web browsers that properly display all features of the interactive profiles are Internet Explorer 6 for Windows and Firefox 1.5 for all platforms. For all browsers, the status bar and JavaScript must be enabled. Firefox also requires "Change status bar text" to be checked under Advanced JavaScript Options. Caution–other browsers may result in spurious or no information given in the status window. The printable and interactive profiles can be viewed from the Profiles page or from links on the trackline maps.
The trace files for 95LCA03 line PRSB_11A and 96LCA02 lines PR296_B and PR296_E were divided into two or more trace files each (e.g., PRSB_11A became PRSB_11Aa and PRSB_11Ab) because the original total number of traces exceeded the maximum allowed by the processing software. Only the upper 100 ms of a total 125 ms are displayed on the 95LCA03 printable profiles because little useful information was observed deeper in the sections.
Detailed information about the navigation systems used can be found in table 1 and the FACS equipment log (12 KB). To view the trackline maps and navigation files, and for more information about these items, see the Navigation page.
The Disc Contents page is a diagram of the location of all files and folders contained on this disc and provides links to these files and folders.
To access the information contained on this disc, use a web browser to open the file index.html. This report is divided into five sections: Navigation Data and Maps, Seismic Profiles, Field Activity Logs, Metadata, and Software. Links at the top and bottom of each page provide access to these sections. This report contains links to the USGS and collaborators or other resources that are only accessible if access to the Internet is available while viewing these documents. Warning! The only supported web browsers that properly display all features of the interactive profiles are Internet Explorer 6 for Windows and Firefox 1.5 for all platforms
Funding and/or support for this study were provided by the USGS Coastal and Marine Geology Program and Water Resources Division and the Southwest Florida Water Management District. We thank Erik L. Staub of the USGS in Tampa, Florida, for his assistance in data collection. This document was improved by the reviews of Mark Hansen (USGS) and Julie C. Bernier (ETI Professionals, Inc., contracted by the USGS) at the FISC - St. Petersburg, Florida.
Barry, R.M., Cavers, D.A., and Kneale, C.W., 1975, Recommended standards for digital tape formats: Geophysics, v. 40, p. 344-352. Also available online at: http://www.seg.org/publications/tech-stand.
Lewelling, B.R., Tihansky, A.B., Kindinger, J.L., 1998, Assessment of the hydraulic connection between ground water and the Peace River, west-central Florida: U.S. Geological Survey Water Resources Investigations Report 97-4211, 96 p. Also available online at: http://fl.water.usgs.gov/Abstracts/wri97_4211_lewelling.html.
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.
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