U.S. Geological Survey
2011
PNG formatted images of EdgeTech SB-512i seismic-reflection profiles collected by the U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center offshore of the Gulf Islands, MS, 2010.
1.0
raster digital data
Open-File Report
2010-1178
Woods Hole Coastal and Marine Science Center, Woods Hole, MA
U.S. Geological Survey, Coastal and Marine Geology Program
https://doi.org/10.3133/ofr20101178
https://pubs.usgs.gov/of/2010/1178/html/GIS_catalog.html
https://pubs.usgs.gov/of/2010/1178/GIS_catalog/Seisimage/10cct02_seisimage.zip
Elizabeth A. Pendleton
Wayne E. Baldwin
William W. Danforth
Nancy T. Dewitt
Arnell S. Forde
David S. Foster
Kyle W. Kelso
William R. Pfeiffer
Aaron M. Turecek
James G. Flocks
David C. Twichell
2011
Geophysical Data from offshore of the Gulf Islands National Seashore, Cat Island to Western Horn Island, Mississippi
1.0
Open-File Report
2010-1178
Reston, VA
U.S. Geological Survey
https://pubs.usgs.gov/of/2010/1178/
In 2010, the U.S. Geological Survey in Woods Hole, MA and St. Petersburg, FL, in partnership with the U.S. Army Corps of Engineers, Mobile District conducted geologic mapping to characterize the seafloor and shallow subsurface stratigraphy offshore of the Gulf Islands of Mississippi. The mapping was carried out during two cruises in March, 2010 on the R/V Tommy Munro of Biloxi, MS. Data were acquired with the following equipment: an SEA Ltd SwathPlus interferometric sonar (both 234 kHz and 468 kHz systems), a Klein 3000 and a Klein 3900 dual frequency sidescan-sonar, and an Edgetech 512i chirp subbottom profiling system. The long-term goal of this mapping effort is to produce high-quality, high-resolution geologic maps and geophysical interpretations that can be utilized to identify sand resources within the region and better understand the Holocene evolution and anticipate future changes in this coastal system. More information on the field work can be accessed from the Woods Hole Coastal and Marine Science Center Field Activity webpage https://cmgds.marine.usgs.gov/fan_info.php?fan=2010-012-FA or the St. Petersburg Coastal and Marine Geology InfoBank https://walrus.wr.usgs.gov/infobank/m/m210gm/html/m-2-10-gm.meta.html.
PNG images of each seismic profile were generated in order to incorporate images of the seismic data into Geographic Information System (GIS) projects and data archives utilizing HTML. These PNG images represent approximately 492 km of chirp seismic data collected with the EdgeTech SB-512i in 2010. This format is universal and yields an easily browseable pictorial view of the seismic profiles. Each profile image is hotlinked to its corresponding trackline navigation contained within a polyline shapefile ('10cct02_SeismicTrackline.shp'), and even 500 shot-point locations are available in a point shapefile ('10cct02_SeismicShot_500.shp). All of these data are available in an ESRI ArcMap project, as well as separate .zip archives on this digital data DVD archive (https://pubs.usgs.gov/of/2011/1178/GIS_catalog/).
20100320
20100328
ground condition
None planned
-89.035786
-88.637281
30.215336
30.126883
USGS Metadata Identifier
USGS:5defd5bd-cbfe-4075-9fab-9b1b5b11c3a3
None
U.S. Geological Survey
USGS
Woods Hole Coastal and Marine Science Center
WHCMSC
St. Petersburg Coastal and Marine Science Center
Coastal and Marine Geology Program
CMGP
PNG
seismic-reflection
SEGY
profiles
seismic
subbottom
image
chirp
EdgeTech
SB-512i
R/V Tommy Munro
St. Petersburg field activity serial number 10cct02
ISO 19115 Topic Category
geoscientificInformation
oceans
imageryBaseMapsEarthCover
USGS Thesaurus
sub-bottom profiling
image collections
marine geophysics
None
Mississippi
Gulf Islands
North Central Gulf Coast
United States
West Ship Island
East Ship Island
Horn Island
Dog Key Pass
Camille Cut
Petit Bois Island
Gulfport Ship Channel
Gulf of Mexico
Cat Island
none
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
David C. Twichell
U.S. Geological Survey
Oceanographer
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700x2266
(508) 457-2310
dtwichell@usgs.gov
https://pubs.usgs.gov/of/2010/1178/GIS_catalog/Seisimage/STPETE_seisimage.png
PNG image of seismic-reflection profile
PNG
Microsoft Windows XP Professional x64 Edition Version 2003 Service Pack 2
John Stockwell
2008
CWP/SU: Seismic Uni*x
document
Golden, CO
Center for Wave Phenomena - Colorado School of Mines
http://www.cwp.mines.edu/cwpcodes/title_page.html
Paul Henkart
2007
SIOSEIS
document
LaJolla, CA
Scripps Institution of Oceanography, University of California - San Diego
http://sioseis.ucsd.edu/title_page.html
Michael W. Norris
Alan K. Faichney
2002
SEGY Rev.1 Data Exchange Format1
document
Tulsa, OK
Society of Exploration Geophysicists
http://www.seg.org/documents/10161/77915/seg_y_rev1.pdf
Processed seismic data were converted to portable network graphic (PNG) format for ease of seismic trace display. Quality control was conducted during processing.
Data Quality Problems:
Poor sea-state conditions periodically created problems with acquisition of the chirp seismic data during the 10cct02 cruise. In most instances, heave removal processing (described in processing steps 2-4) greatly minimized the effects of sea state in the final trace data. However, the effects of particularly larger swells do remain within some of the final profiles. In the interest of preserving as much potentially interesting seafloor information as possible, we decided not to lengthen seafloor smoothing filters to the widths that would have been required to remove larger swells. We suggest viewing the PNG image of line 10i172_stk.png to illustrate heave artifacts that remain after the processing. While sea floor heave has been subdued, some of the predictable undulation of seafloor and subsurface reflections persist. In light of these problems, we caution the interpretation of seafloor features that appear to be at the same scale of heave artifacts within profiles that are obviously affected by problematic sea states.
Only the portions of this seismic-reflection survey that lie west of Petit Bois Island are included as processed PNG images for this report. Additional seismic-data acquired east of this study area will be included in a future report.
The SB-512i was towed astern of the R/V Tommy Munro approximately 3 m below the surface. Differential Global Positioning System (DGPS) navigation coordinates were obtained from the Coda Octopus F190 motion reference unit (equipped with Omnistar HP) antenna and EdgeTech Discover acquisition software logged the navigation coordinates to individual trace headers in the Society of Exploration Geophysicists Y (SEG-Y), revision 1 format (Norris and Faichney, 2002). Horizontal offsets between the navigation antenna and the towfish were not accounted for during acquisition, nor was the vertical draft of the towfish beneath the sea-surface. Navigational uncertainty is increased due to fish motion behind the vessel, which is caused by sea state and vessel speed induced changes in the angle and scope of the tow cable. Resulting positional accuracy is assumed to be better than 20 m.
U.S. Geological Survey
unknown
Information unavailable from original metadata.
disc
20100320
20100328
ground condition
Information unavailable from original metadata.
High-resolution chirp seismic-reflection profiles were collected using an EdgeTech Geo-Star Full Spectrum Sub-bottom (FSSB) system and SB-512i towfish (0.5-12 kHz) (EdgeTech, 2008). EdgeTech Discover acquisition software was used to control the Geo-Star topside unit and digitally log trace data in the Society of Exploration Geophysicists Y (SEG-Y), revision 1, standard format (Norris and Faichney, 2002). The SB-512i towfish was towed astern of the vessel approximately 3 m below the water surface. Differential Global Positioning System (DGPS) navigation coordinates were obtained from the Coda Octopus F190 motion reference unit (equipped with Omnistar HP) antenna and logged to the SEG-Y trace headers. Data were acquired using a 0.5 to 8 kHz frequency sweep, a 5 millisecond pulse length, a 0.25 second shot rate, a 46 microsecond sample interval, and a 100 millisecond record length. A total of 492 km of seismic data from this survey are included in this shapefile.
An executable C-shell script called on Seismic Unix (version 4.1) to: 1) read the raw SEG-Y data and write a Seismic Unix file; 2) apply automatic gain control; and 3) write the processed traces to new SEG-Y files.
201003
Arnell (Harrison) Forde
U.S. Geological Survey
Geologist
mailing and physical address
600 Fourth Street South
St. Petersburg
FL
33701
USA
727-803-8747 x3111
727-803-2032
aharrison@usgs.gov
An executable C-shell script called on SIOSEIS (version 10.2.25) to: 1) read the processed SEG-Y data from the previous step and create shot gathers containing two consecutive traces; 2) create a stacked trace from the two trace gathers while maintaining the navigation coordinates (in arc-seconds) from the header of the first trace in each; and 3) write the stacked traces to new SEG-Y files. This stacking flow ensured that the resulting traces were spaced greater than 0.5 m apart along the trackline, which is a prerequisite for the traces to be loaded into GeoGraphix SeisVision (version R5000) for digital interpretation.
201010
Elizabeth Pendleton
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700x2259
(508) 457-2310
ependleton@usgs.gov
An executable C-shell script called on SIOSEIS (version 10.2.25) to use the process WBT specifying the threshold option to predict the vertical location of the sea floor by identifying the first amplitude in each trace that exceeded a user defined value. Two-way travel times (milliseconds) to the sea floor at each trace were recorded the trace headers and saved to an ASCII text file.
201009
Elizabeth Pendleton
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700x2259
(508) 457-2310
ependleton@usgs.gov
All SEG-Y trace data were imported into GeoGraphix SeisVision (version R5000), a 2-dimensional, digital seismic interpretation software, and seafloor values were imported as ASCII text horizon data. The horizon smooth utility was used to remove spurious seafloor values for discrete traces and corrected values were exported to a new ASCII text file.
201009
Elizabeth Pendleton
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700x2259
(508) 457-2310
ependleton@usgs.gov
An executable C-shell script called on SIOSEIS (version 10.2.25) to remove sea surface heave and mute water column portions of the traces by: 1) loading the corrected seafloor times into the SEG-Y trace headers; 2) using process 'SWELL' to suppress the heave by shifting traces vertically; and 3) muting each trace between time zero and the time of the smoothed sea floor pick using process 'MUTE', thus removing noise within the water column. Changes to the traces within each profile were saved to new "heave corrected" SEG-Y files, which were used for creation of PNG browse images and digital interpretation.
201009
Elizabeth Pendleton
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700x2259
(508) 457-2310
ependleton@usgs.gov
A script was run that used Seismic Unix (version 4.1) to read the SEG-Y files and plot the data as 8-bit gray scale Postscript files using the Seismic Unix 'psimage' algorithm. All images were created with a horizontal scale of 200 traces per inch. Images were plotted within a constant 12-inch vertical window of 50 milliseconds (Two-Way Travel Time) duration. The Postscript images were then converted to PNG format using ImageMagick (version 5.5.6).
201009
Elizabeth Pendleton
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700x2259
(508) 457-2310
ependleton@usgs.gov
Edits to the metadata were made to fix any errors that MP v 2.9.36 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). The link to the data in the Identification_Information section had to be fixed. The link to the data in the Distribution_Information section had to be fixed. Attempted to modify http to https where appropriate. Added a landing page link as the first link in the identification section. Updated the link to the field activity. The source information was incomplete and had to be modified to meet the standard. The distribution format name was modified in an attempt to be more consistent with other metadata files of the same data format. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent.
20171026
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
USGS Thesaurus keywords added to the keyword section.
20180720
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Crossref DOI link was added as the first link in the metadata.
20191118
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Added keywords section with USGS persistent identifier as theme keyword.
20200908
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Raster
pixel
Elizabeth Pendleton
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700x2259
(508) 457-2310
ependleton@usgs.gov
Downloadable Data
Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
PNG
WinZip (version 14.5) files contains compressed images of processed seismic-reflection profiles as well as associated metadata.
Use WinZip or pkUnzip
89.0
https://pubs.usgs.gov/of/2010/1178/GIS_catalog/Seisimage/10cct02_seisimage.zip
Data can be downloaded via the World Wide Web (WWW)
DVD-ROM
4.75
Gbytes
UDF
none
Digital copies of these chirp seismic data may also be obtained in the SEG-Y Rev. 1 standard format upon request. The data would be packaged on DVD, and contain the chirp-processed, envelope traces.
These data can be viewed with any PNG image viewing software.
20240318
Elizabeth Pendleton
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700x2259
(508) 457-2310
whsc_data_contact@usgs.gov
The metadata contact email address is a generic address in the event the person is no longer with USGS. (updated on 20240318)
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998
local time
None
None