Data Series 100

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Home | Acronyms | Contents | Navigation | Profiles | Logs | Metadata | Software

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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 DVD 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.

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System Requirements

This DVD disc is readable on any computing platform that has standard DVD-R driver software installed. The minimum software requirements are a web browser, Acrobat Reader, and a text editor.

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Project Summary

In August and September of 1993 and January of 1994, the U.S. Geological Survey, under a cooperative agreement with the St. Johns River Water Management District (SJRWMD), conducted geophysical surveys of Kingsley Lake, Orange Lake, and Lowry Lake in northeast Florida. This report serves as an archive of unprocessed digital boomer seismic reflection data, trackline maps, navigation files, GIS information, observer's logbook, Field Activity Collection System (FACS) logs, and formal FGDC metadata. A filtered and gained GIF image of each seismic profile is 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). Examples of SU processing scripts and in-house (USGS) software for viewing SEG-Y files (Zihlman, 1992) are also provided.

The data archived here were collected under a cooperative agreement with the St. Johns River Water Management District as part of the USGS Lakes and Coastal Aquifers (LCA) Project. For further information about this study, refer to http://coastal.er.usgs.gov/stjohns, Kindinger and others (1994), and Kindinger and others (2000).

The USGS Florida Integrated Science Center (FISC) - Coastal and Watershed Studies in St. Petersburg, Florida, assigns a unique identifier to each cruise or field activity. For example, 93LCA01 tells us the data were collected in 1993 for the Lakes and Coastal Aquifers (LCA) Project and the data were collected during the first field activity for that project in that calendar year. For a detailed description of the method used to assign the field activity ID, see http://walrus.wr.usgs.gov/infobank/programs/html/definition/activity.html.

The boomer 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 (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. Acquisition geometery for 94LCA01 is recorded in the operations logbook. No logbook exists for 93LCA01. Table 1 displays acquisition parameters for both field activities. For more information about the acquisition equipment used, refer to the FACS equipment logs.

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 more information about these files. Processed profiles can be viewed as GIF images from the Profiles page. Refer to the Software page for details about the processing and examples of the processing scripts.

Detailed information about the navigation systems used for each field activity can be found in Table 1 and the FACS equipment logs. To view the trackline maps and navigation files, and for more information about these items, see the Navigation page.

The original trace files were recorded in nonstandard ELICS format and later converted to standard SEG-Y format. The original trace files for 94LCA01 lines ORJ127_1, ORJ127_3, and ORJ131_1 were divided into two or more trace files (e.g., ORJ127_1 became ORJ127_1a and ORJ127_1b) because the original total number of traces exceeded the maximum allowed by the processing system. Digital data were not recoverable for 93LCA01 line KIN826_1, and digital data were not recorded for 93LCA01 line KIN826_6 and 94LCA01 lines ORJ127_2, ORJ128_1, ORJ128_3, and ORJ128_4. No data were collected for 93LCA01 lines KIN824_2, KIN826_3, ORJ828_1, ORJ828_5, ORJ828_7, LOW830_7, and LOW91_3. 93LCA01 lines 825TST, KIN824_1, KIN824_5, KIN826_2, KIN826_5, KIN827_2, ORJ828_3, ORJ828_4, LOW830_2, LOW830_3, LOW830_5, and LOW91_4 and 94LCA01 line ORJ131_1a are missing navigation for the first 100 shots or more. 93LCA01 lines KIN824_1, ORJ828_2, LOW830_4, and LOW91_5 are missing navigation for the last 150 to 2,676 shots. No navigation is available for 93LCA01 lines TEST520, TST1, KIN824_3, and KIN824_4, and navigation is intermittent for 93LCA01 line LOW91_4. On the trackline maps, the location of missing navigation data within a line is inferred by linear interpolation of the first and last known data points.

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DVD Organization

The Disc Contents page is a diagram of the location of all files and folders mentioned in the text and provides links to some of these files and folders.

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Getting Started

To access the information contained on this disc, use a web browser to open the file index.htm located at the top level of the disc. 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.

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Acknowledgments

Funding and/or support for this study were provided by the USGS Coastal and Marine Geology Program and the St. Johns River Water Management District. We thank boat driver Shane Dossat of the SJRWMD for his assistance in data collection. This document was improved by the reviews of Mario Fernandez and Charles W. Holmes of the USGS in St. Petersburg, Florida.

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References Cited

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.

Kindinger, J.L., Davis, J.B., Flocks, J.G., 1994, High-resolution single-channel seismic reflection surveys of Orange Lake and other selected sites of north central Florida: U.S. Geological Survey Open-File Report 94-616, 48 p. Also available online at: http://coastal.er.usgs.gov/stjohns/ofr616.

Kindinger, J.L., Davis, J.B., Flocks, J.G., 2000, Subsurface characterization of selected water bodies in the St. Johns River Water Management District, northeast Florida: U.S. Geological Survey Open-File Report 00-180, 46 p. Also available online at: http://coastal.er.usgs.gov/publications/ofr/00-180.

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.