Title Page - Introduction - Cruise Report - Equipment - Chirp Data - Shotpoint Maps - Navigation - Pictures - Metadata
In 1999, the Gulf of Mexico Fishery Management Council recommended that NOAA's
National Marine Fisheries Service establish two approximately 11-square-mile
areas on the shelf edge in the northeastern Gulf of Mexico as no-fishing areas.
One of the areas, the Madison-Swanson Marine Protected Area (MPA) lies about
100 km south of Panama City, Florida. The second area, Steamboat Lumps MPA
lies about 150 km SSE of Madison-Swanson. The high-resolution seismic-reflection
data contained herein were collected as part of a larger study of the effectiveness
of no-fishing reserves in protecting grouper spawning aggregations. These
subbottom profiles will be used in conjunction with other data to map the
seafloor geology and the character and extent of benthic habitats within and
surrounding the two MPAs. They show the shape and acoustic impedence of the
seafloor and the thicknesses and orientations of shallow subsurface horizons.
These data may be helpful in the following applications:
The data and information on these
DVD-ROMs are formatted for access and download via WWW information browser (e.g.,
Internet Explorer, Netscape, Opera). Hyperlink references to additional Internet-resident
information (WWW) will not function if your computer is not actively connected
to the Internet via ISP or online LAN. These web links are functional at publication, but there is no guarantee that they will not change or be discontinued.
The archived Chirp subbottom data are in standard Society of Exploration Geologists
(SEG) SEG-Y format (Barry and others, 1975) and may be downloaded
for processing with software such as Seismic
Unix (www.cwp.mines.edu/cwpcodes/index.html) or SIOSEIS (sioseis.ucsd.edu). The subbottom data
were recorded on the ISIS data acquisition system in QMIPS format. Chirp subbottom
channel extracted from raw QMIPS format sonar files and converted to 16-bit
Int. SEG-Y format using the program QMIPSTOSEGY. Even though the data are in
SEG-Y format, it is not the conventional time series data (e.g. voltages or
pressures), but rather instantaneous amplitude or envelope detected and therefore
all of the amplitudes are positive (though not simply rectified). DOS and Microsoft
Windows compatible software for plotting SEG-Y files (PLOTSEIS)
and viewing SEG-Y headers (DUMPSEGY)
is located in the PLOTSEIS directory. Processed chirp profiles (GIF images)
may be viewed on this DVD-ROM with your WWW browser.
Subdirectory PLOTSEIS: This directory contains the DOS programs for plotting SEG-Y files and viewing SEG-Y headers.Directory HTMLDOCS: Contains the necessary HTML files and supporting graphics to allow the user access to the DVD-ROM via any World Wide Web (WWW) browser.
Subdirectory SU: Contains the Seismic UNIX (www.cwp.mines.edu/cwpcodes/index.html) scripts used to process and plot the chirp subbottom data and extract shot navigation from the SEG-Y headers
Subdirectory SHOTNAV: Contains the shot navigation data that were collected during the cruise using a USGS differential GPS systemDirectory SEGY: Contains the Chirp SEG-Y format data. These data were collected using a Datasonics SIS-1000 Chirp subbottom profiler. The SEG-Y data were logged on a Triton-Elics ISIS acquisition system. The SEG-Y format is documented in HTML.
Title Page - Introduction - Cruise Report - Equipment - Chirp Data - Shotpoint Maps - Navigation - Pictures - Metadata