Bratton, John F. , and Bergeron, Emile, 2014, Chirp seismic-reflection profile data in JPEG image format Collected in the Indian River Bay, Delaware, on April 13, 2010, on U.S. Geological Survey Field Activity 2010-006-FA: Open-File Report 2011-1039, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.This is part of the following larger work.Online Links:
- <http://pubs.usgs.gov/of/2011/1039/data/seismics/seismic_jpegs.zip>
- <http://pubs.usgs.gov/of/2011/1039/html/ofr2011-1039-catalog.html>
Cross, V.A., Bratton, J.F., Michael, H.A., Kroeger, K.D., Green, A., and Bergeron, E., 2014, Continuous Resistivity Profiling and Seismic-Reflection Data Collected in April 2010 from Indian River Bay, Delaware: Open-File Report 2011-1039, U.S. Geological Survey, Reston, VA.Online Links:
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The purpose of this dataset is to provide the seismic-reflection profile data in JPEG image format, which provides information about the sub-surface geology in the survey area.
segyread tape=$1.sgy verbose=1 vblock=1000 conv=1 endian=0 | \ segyclean > $1.suThis is a portion of a larger script used to extract the navigation from the SEG-Y headers. The script is initiated with a shell script so that every file with the "sgy" extension is read and converted to the SU format.
Person who carried out this activity:
(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@usgs.gov
Data sources produced in this process:
plotchirp 0 0.02 l4f1.001 7 98This runs the plotchirp script with the parameters of start time of trace 0, end time of trace 0.02 seconds, l4f1.001 is the seismic file, 7 refers to the plot height in inches, and 98 is the percent black clip (where higher is lighter). The plotchirp script is as follows:
plotchirp:
#! /bin/csh ## PLOTCHIRP echo "Process plotchirp usage:" echo " plotchirp tmin tmax sufile hbox clip" echo " tmin and tmax (seconds) to define the vertical plot window" echo " ie, 0 0.25 (window 0 to 250 ms)" echo " the SU input file excluding the .su extension" echo " hbox is the vertical plot size in inches" echo " enter the % black clip ie, 95 (higher is lighter)" echo " " # get number of traces to be used in plot scale echo "getting the total number of traces" set numtraces = `surange < $3.su | grep traces | awk ' {print($1)}' ` echo "number of traces = "$numtraces # get ffid range for input echo "getting the range of FFID's" set ffidmin = `surange < $3.su | grep tracr | awk ' {print($2)}' ` set ffidmax = `surange < $3.su | grep tracr | awk ' {print($3)}' ` echo "The minimum FFID is "$ffidmin echo "The maximum FFID is "$ffidmax echo " " echo "Setting the sort order (data window), Set gain parameters" suwind key=tracr min=$ffidmin max=$ffidmax itmin=$1 tmin=$1 tmax=$2 verbose=0 < $3.su | \ suchw key1=delrt a=0 | \ suchw key1=tstat a=0 | suchw key1=muts a=0 | suchw key1=mute a=0 > $3.tmp echo "Set scaling for PS plot" # set the plot X size based on the number of traces/inch set wbox = `expr $numtraces / 40` echo "the plot length =" $wbox "inches" echo # set the plot Y size (hbox) in inches set tmin = $1 echo "tmin ="$tmin set tmax = $2 echo "tmax ="$tmax set hbox = $4 echo "the plot height=" $hbox "inches" # PLOT POSTSCRIPT IMAGE # Change percentile for determining black clip value to adjust plot contrast # Higher bperc gives lighter plot - wclip=0 sets 0 and - amp. to white echo "Making the PostScript plot" supsimage wbox=$wbox hbox=$hbox \ ybox=0.5 \ x1beg=$1 x1end=$2 \ d1num=0.01 d2num=500 \ d2=1 \ n1tic=10 n2tic=5 \ bperc=$5 wclip=0 \ grid1=dot grid2=dot \ title="424 Chirp $3 SHOTS $ffidmin-$ffidmax" \ label1="TWT [s]" label2="SHOT" \ < $3.tmp > ../ps_files/$3.ps rm $3.tmp echo "Making jpeg" convert ../ps_files/$3.ps ../jpeg_files/$3.jpg # Save the processing runline history for future processing echo "plotchirp $1 $2 $3 $4 $5" >> Proc.log # Remove files not needed rm ../ps_files/*.ps
Person who carried out this activity:
(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@usgs.gov
Data sources produced in this process:
Jr., J.W. Stockwell , and Cohen, J.K., 2008, The New SU User's Manual (version 4.0): Center for Wave Phenomena - Colorado School of Mines, Golden, CO.Online Links:
The navigation system used was a Lowrance 480M with an LGC-2000 Global Positioning System (GPS) antenna. The antenna was located above the seismic towfish tow point. The system towfish was attached by a short line to a cleat on a 2 x 6 board that was clamped across the bow of the boat. The towfish was on the starboard side of the boat, approximately 0.5 meters below the water surface.
Although bathymetry was not recorded directly with this system, bathymetry can be derived by tracing the seafloor reflector in the seismic-reflection profiles. The seismic towfish was attached to a cleat by a short line on the starboard side of the boat. The transducer draft was approximately 0.5 m below the water surface. The draft offset was not included in the data acquisition.
A JPEG format image is available for every seismic-reflection profile line collected on this cruise.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None.
- Use_Constraints:
- The 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.
(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@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.
Data format: | The WinZip (v. 14) file contains all the JPEG format images of the seismic-reflection profiles, as well as the associated metadata. in format JPEG Size: 19.9 MB |
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Network links: |
<http://pubs.usgs.gov/of/2011/1039/data/seismics/seismic_jpegs.zip> <http://pubs.usgs.gov/of/2011/1039/html/ofr2011-1039-catalog.html> <http://dx.doi.org/10.3133/ofr20111039> |
The user must have software capable of uncompressing the zip file. These files can then be viewed with any JPEG image viewing software.
(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@usgs.gov