U.S. Geological Survey
2014
BC_tracklines.shp: Trackline navigation for EdgeTech SB-512i chirp seismic-reflection data collected in May 2012 by the U.S. Geological Survey within the Baltimore Canyon, mid-Atlantic margin (Esri polyline shapefile, Geographic, WGS 84)
1.0
vector digital data
Open-File Report
2014-1118
Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts
U.S. Geological Survey, Coastal and Marine Geology Program
https://pubs.usgs.gov/of/2014/1118/data/Baltimore_Canyon/GIS/BC_tracklines.zip
Jeffrey Obelcz
Daniel S. Brothers
Uri S. ten Brink
Jason D. Chaytor
Charles R. Worley
Eric M. Moore
2014
Chirp Seismic-Reflection Data From the Baltimore, Washington, and Norfolk Canyons, U.S. Mid-Atlantic Margin
1.0
Open-File Report
2014-1118
Reston, Virginia
U.S. Geological Survey
https://dx.doi.org/10.3133/ofr20141118
https://pubs.usgs.gov/of/2014/1118/
A large number of high-resolution geophysical surveys between Cape Hatteras and Georges Bank have been conducted by federal, state, and academic institutions since the turn of the century. A major goal of these surveys is providing a continuous view of bathymetry and shallow stratigraphy at the shelf edge in order to assess levels of geological activity during the current sea level highstand. In 2012, chirp seismic-reflection data was collected by the U.S. Geologial Survey aboard the motor vessel Tiki XIV near three United States mid-Atlantic margin submarine canyons. These data can be used to further our understanding of passive continental margin processes during the Holocene, as well as providing valuable information regarding potential submarine geohazards. For more information on the U.S. Geological Survey involvement in this effort, see <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2012-005-FA>.
This dataset contains trackline navigation for over 375 km of EdgeTech SB-512i Chirp seismic-reflection data collected by the U.S. Geological Survey during Woods Hole Coastal and Marine Science Center cruise 2012-005-FA within Baltimore Canyon. This dataset provides the GIS trackline navigation that corresponds readily with images produced from the seismic-reflection data. The dataset also serves as a navigation archive.
20120523
1011 (UTC)
20120524
1126 (UTC)
ground condition of survey on dates 20120523-20120524
None planned
-74.043422
-73.719950
38.326086
37.872736
General
U.S. Geological Survey
USGS
Coastal and Marine Geology Program
CMGP
Woods Hole Coastal and Marine Science Center
WHCMSC
Seafloor
Marine Geology
field activity 2012-005-FA
field activity number 12005
USGS CMG InfoBank ID T-05-12-MC
seismic profile
navigation tracklines
seismic navigation
seismic reflection
chirp
EdgeTech
512i
M/V Tiki XIV
M/V Tiki 14
continental margin
submarine canyon
geohazards
seismic-reflection data
ISO 19115 Topic Category
oceans
location
General
North America
United States
Atlantic Ocean
Maryland
mid-Atlantic margin
Baltimore Canyon
Baltimore Canyon Trough
General
Seafloor
Subsurface
General
2012
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 source of this information.
Jeffrey Obelcz
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Road
Woods Hole
MA
02543-1598
U.S.A.
508-548-8700 x. 2245
508-457-2310
jobelcz@usgs.gov
https://pubs.usgs.gov/of/2014/1118/data/Baltimore_Canyon/GIS/BC_tracklines_browse.jpg
EdgeTech 512i trackline navigation within and around Baltimore Canyon
JPEG
Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; ESRI ArcCatalog 9.3.1.1850
John Stockwell
2011
CWP/SU: Seismic Uni*x
Golden, CO
Center for Wave Phenomena - Colorado School of Mines
http://www.cwp.mines.edu/cwpcodes/
Paul Henkart
2011
SIOSEIS
La Jolla, California
Scripps Institution of Oceanography, UC San Diego
http://sioseis.ucsd.edu/
Michael W. Norris and Alan K. Faichney
2002
SEGY Rev. 1 Data Exchange Format 1
Tulsa, OK
Society of Exploration Geophysicists
http://www.seg.org/documents/10161/77915/seg_y_rev1.pdf
All attributes were checked in a consistent manner.
Any spurious data points were removed during processing. For each seismic trackline there is one seismic-profile image. No duplicates exist.
Lines were serially recorded during the survey in the format "LXF1". When a file is named "LXF2" or has a file number greater than 2, the recording parameters were usually changed (record length and shot rate), as recorded in the ship's log. The following lines were either not recorded or excluded from this data release: L3F2 (neglligible length), L4F1 (line name error, never recorded), L15F1 (negligible length), L25F2 (small, noisy, no features of interest), L47F1 (negligible length).
The SB-0512i was towed 3 meters below the sea surface approximately 10 m astern of the M/V Tiki XIV. Position data were provided by a Differential Global Positioning System (DGPS) navigation receiver mounted on the port aft side of the cabin. Layback positions, which account for the linear distance between the shipboard DGPS receiver and the towed chirp fish, were not calculated or accounted for in the navigation. Positional accuracy is assumed to be +/- 20 m; layback calculations do not account for fish motions behind the vessel caused by sea state/ship speed changes in angle and scope of the tow cable.
U.S. Geological Survey
Unpublished Material
raw seismic navigation
20120523
1011
20120524
1126
ground condition
Seismic-reflection data acquisition: Chirp seismic data were collected using an EdgeTech SB-0512i towfish (0.5-4.5 kHz pulse, 50 ms pulse length, except for L19F3-L28F1, which were 0.5-2.7 kHz, 40 ms pulse length), which was towed astern of the M/V Tiki XIV of Ocean City, MD. Chesapeake Technologies' SonarWiz (v.4.04.0031) seismic acquisition software was used to control the chirp, digitally log trace data in the SEG-Y Rev. 1 format (IEEE floating point), and record GPS navigation coordinates to the SEG-Y trace headers (in arc seconds of Latitude and Longitude, multiplied by a scalar of 100). Trace lengths are constant within lines, but vary from line to line due to variable water depth in the survey area (the minimum trace length was 250 ms and the maximum 1400 ms). This yields a range of samples per trace from approximately 5435 (250 ms trace length) to 30435 (1400 ms trace length). Sample interval was kept at a constant .000046 s. The ping rate was set to be consistent with the trace length, so it varied between 250 ms and 1400 ms.
Seismic Unix (version 4.2) was used to read SEG-Y files, write a Seismic Unix file, and extract SEG-Y trace header information, including shot number, longitude, latitude, year, Julian day, and time of day (UTC). Header information from each SEG-Y file was saved to text files after an AWK (no version) filter was used to maintain shots at multiples of 100 and shots with unique navigation coordinates. End shots and shots at multiples of 100 may not have unique navigation coordinates. Separate text files containing unique shot navigation were also produced.
201206
Jeffrey Obelcz
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Road
Woods Hole
MA
02543-1598
USA
508-548-8700 x. 2245
jobelcz@usgs.gov
The 100 shot interval text files produced from process step 1 were concatenated into a comma-delimited text file, then the text file was imported into ArcMap (version 9.3) using 'Add XY data' and saved as points (Geographic, WGS84) in the Esri shapefile format.
201305
Jeffrey Obelcz
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Road
Woods Hole
MA
02543-1598
USA
508-548-8700 x. 2245
jobelcz@usgs.gov
The shapefile containing 100 shot interval positions, created in the previous step, was used as an input for VACExtras (version 3.1.2), a VB collection of tools developed by VeeAnn Cross (USGS-WHSC), which converts point data to a new polyline shapefile ('BC_tracklines.shp').. The 'line' field was used to define which points were used to generate each polyline feature, and the fields "lon " (line beginning longitude), "lat" (line beginning latitude), "jd_hour_mi" (line time start), "year" (year of data acquisition), "lon_end" (line ending longitude), "lat_end" (line ending latitude), and "jd_hou_end" (line ending time) were included as attributes in the output shapefile.
201305
Jeffrey Obelcz
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Road
Woods Hole
MA
02543-1598
USA
508-548-8700 x. 2245
jobelcz@coastal.edu
The attribute "hlink" was added to the shapefile in ArcMap 9.3.1 and populated with the relative path and seismic-reflection profile image filename corresponding to the trackline. This allows the user to "hotlink" to the seismic profiles from within ArcMap. In order for this to work, the user must activate the "Hyperlinks" option of the dataset properties display tab. The field to use is "hlink" and the link type is a document. In the ArcMap - File - Document properties the user needs to supply the hyperlink base This is the remainder of the file location path prior to the data folder indicated in the "hlink" attribute.
201401
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
mailing and physical address
384 Woods Hole Road
Woods Hole
Massachusetts
02543-1598
USA
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Vector
String
79
0.000001
0.000001
Decimal degrees
D_WGS_1984
WGS_1984
6378137.000000
298.257224
BC_tracklines
trackline for seismic profiles
USGS
FID
Internal feature number.
ESRI
Sequential unique whole numbers that are automatically generated.
Shape
Feature geometry.
ESRI
Coordinates defining the features.
Id
attribute automatically generated by the software that converts points to lines.
software
0
0
unitless
line
line name corresponding to PNG format seismic-reflection profile images. The format of the linename is a combination of the survey line and the processing of the SEG-Y data. The line number is in the format LXXFY where XX is the line number, and Y is the file number on that line (in case more than one file was used to acquire a line). Lines with "topmute_sf" indicate that the software SIOSEIS was used to mute the first 10 ms of each seismic trace and then used identify the seafloor and then use this information to process 'swell' to minimize the effect of sea surface heave. Lines with only "sf" in the name had to have the seafloor manually picked and then insert that information into the SEG-Y header to enable the sea surface heaving to be minimized.
USGS
character set.
lon
longitude value of first shot of line (decimal degree, WGS84)
USGS
-74.032644
-73.723133
decimal degrees
0.000001
lat
latitude value of first shot of line (decimal degree, WGS84)
USGS
37.872736
38.321733
decimal degrees
0.000001
year
calendar year data were collected
USGS
2012
2012
year
1
jd_hour_mi
time of first shot of line (Julian Day:hour:minute:second). Julian day is the integer number representing the interval of time in days since January 1 of the year.
USGS
Although the value is represented as a number, the number as a whole doesn't have a meaning. This value has to be broken down to its separate components (julian day, hour, minute, second) to have numerical significance.
lon_end
longitude value of last shot of line (decimal degree, WGS84)
USGS
-74.039911
-73.722119
decimal degrees
0.000001
lat_end
latitude value of last shot of line (decimal degree, WGS84)
USGS
37.873297
38.322036
decimal degrees
0.000001
jd_hou_end
time of last shot of line (Julian Day:hour:minute:second). Julian day is the integer number representing the interval of time in days since January 1 of the year.
USGS
Although the value is represented as a number, the number as a whole doesn't have a meaning. This value has to be broken down to its separate components (julian day, hour, minute, second) to have numerical significance.
hlink
Relative path and filename that can be used to hotlink the trackline to the corresponding seismic-reflection profile image.
U.S. Geological Survey
Character set.
Jeffrey Obelcz
U.S. Geological Survey, Woods Hole Science Center
Geologist
mailing and physical address
384 Woods Hole Road
Woods Hole
MA
02543
USA
508-548-8700 x. 2245
jobelcz@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.
Shapefile
ArcGIS 9.3
Esri polyline shapefile
Trackline navigation for EdgeTech SB-512i chirp seismic-reflection data collected by the U.S. Geological Survey within and around Baltimore Canyon. This also includes associated metadata.
Use WinZip, 7zip, Peazip or pkUnzip. Compressed with WinZip v. 14.0.
0.4 MB
https://pubs.usgs.gov/of/2014/1118/data/Baltimore_Canyon/GIS/BC_tracklines.zip
https://pubs.usgs.gov/of/2014/1118/ofr2014-1118-data-catalog.html
Data can be downloaded via the world wide web (WWW)
none
This zip file contains data available in Esri shapefile format. The zip file also contains associated metadata. The user must have software capable of uncompressing the zip file and displaying the shapefile. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing the data. A free data viewer, ArcExplorer, capable of displaying the data is available from Esri at www.esri.com.
20140623
Jeffrey Obelcz
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Road
Woods Hole
MA
02543-1598
USA
508-548-8700 x. 2245
508-457-2310
jobelcz@usgs.gov
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998
local time