JPEG images of Chirp seismic data collected by the U.S. Geological Survey within the St. Clair River between Michigan and Ontario, Canada, 2008 (JPEG IMAGES)

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Frequently-anticipated questions:

What does this data set describe?

Title:
JPEG images of Chirp seismic data collected by the U.S. Geological Survey within the St. Clair River between Michigan and Ontario, Canada, 2008 (JPEG IMAGES)
Abstract:
In 2008, the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), in cooperation with the U.S. Army Corps of Engineers conducted a geophysical and sampling survey of the riverbed of the Upper St. Clair River between Port Huron, MI, and Sarnia, Ontario, Canada. The objectives were to define the Quaternary geologic framework of the St. Clair River to evaluate the relationship between morphologic change of the riverbed and underlying stratigraphy. This report presents the geophysical and sample data collected from the St. Clair River, May 29-June 6, 2008 as part of the International Upper Great Lakes Study, a 5-year project funded by the International Joint Commission of the United States and Canada to examine whether physical changes in the St. Clair River are affecting water levels within the upper Great Lakes, to assess regulation plans for outflows from Lake Superior, and to examine the potential effect of climate change on the Great Lakes water levels ( <http://www.iugls.org>). This document makes available the data that were used in a separate report, U.S. Geological Survey Open-File Report 2009-1137, which detailed the interpretations of the Quaternary geologic framework of the region. This report includes a description of the suite of high-resolution acoustic and sediment-sampling systems that were used to map the morphology, surficial sediment distribution, and underlying geology of the Upper St. Clair River during USGS field activity 2008-016-FA . Video and photographs of the riverbed were also collected and are included in this data release. Future analyses will be focused on substrate erosion and its effects on river-channel morphology and geometry. Ultimately, the International Upper Great Lakes Study will attempt to determine where physical changes in the St. Clair River affect water flow and, subsequently, water levels in the Upper Great Lakes.
  1. How should this data set be cited?

    U.S. Geological Survey, 2010, JPEG images of Chirp seismic data collected by the U.S. Geological Survey within the St. Clair River between Michigan and Ontario, Canada, 2008 (JPEG IMAGES): Open-File Report 2010-1035, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Denny, Jane F. , Foster, David S. , Worley, Charles R. , and Irwin, Barry J. , 2010, Geophysical data collected from the St. Clair River between Michigan and Ontario, Canada, 2008-016-FA: Open-File Report 2010-1035, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -82.513962
    East_Bounding_Coordinate: -82.402206
    North_Bounding_Coordinate: 43.015465
    South_Bounding_Coordinate: 42.655571

  3. What does it look like?

    <https://pubs.usgs.gov/of/2010/1035/gis_catalog/seisimage/ch_seis_sm.jpg> (JPEG)
    Thumbnail image of representative Chirp sub-bottom profile

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 29-May-2008
    Beginning_Time: 20080601
    Ending_Date: 30-May-2008
    Ending_Time: 20080602
    Currentness_Reference: ground condition

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: raster digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Raster data set. It contains the following raster data types:

      • Dimensions, type Pixel

    2. What coordinate system is used to represent geographic features?

  7. How does the data set describe geographic features?

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

  3. To whom should users address questions about the data?

    Jane Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543
    USA

    508-548-8700 x2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov

Why was the data set created?

JPEG 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 JPEG images represent 80 km of Chirp seismic data collected in 2008 during USGS cruise 08016. This format is universal and yields an easily viewable image of the seismic profiles. Each profile image is hyperlinked to its corresponding trackline navigation contained within a polyline shapefile (08016_Chirp_trk.shp), shot-point locations are available in a point shapefiles (08016_chrip_500sht.shp, 08016_Chirp_100sht.shp). These data are available in an ESRI ArcMap project, as well as separate .zip archives (<https://pubs.usgs.gov/pubs/of/2010/1035/gis_catalog/>).

How was the data set created?

  1. From what previous works were the data drawn?

    (source 1 of 1)
    Source_Contribution:
    The Chirp sub-bottom profiler was deployed off the starboard side of the USGS R/V Rafael. Chirp sub-bottom profiles were collected using a dual-frequency (3.5 and 200 kHz) Knudsen Engineering Limited (KEL) Chirp 3200® system (Knudsen Engineering Limited, 2009). The single-beam water depths from the 200-kHz channel were logged together with navigation in ASCII format. Chirp sub-bottom data with a peak frequency of 3.5 kHz were recorded using Knudsen acquisition software, SounderSuite, in Society of Exploration Geophysicists Y (SEG-Y) format (Barry and others, 1975) with DGPS navigation logged to the SEG-Y file trace headers. The Chirp system was fired at a rate of 0.25 or 0.5 s. The trace length was set to 67 ms. The vertical resolution of this system is approximately 30 cm. A total of 80 km of sub-bottom data were collected

  2. How were the data generated, processed, and modified?

    Date: 2008 (process 1 of 2)
    A script was executed using Seismic Unix (version 4.1) to read the SEG-Y files, write a Seismic Unix file, and extract SEG-Y trace header information, which included shot number, longitude (arc seconds), latitude (arc seconds), year, filename, Julian day, and time of day (UTC). Geographic coordinates (WGS84) were converted to UTM zone 17 coordinates (WGS84) using Proj (version 4.6.0). Before saving the header information to a text file, the data were filtered using AWK (no version) to save only unique shot point locations. The unique shot navigation for each seismic line were then concatenated into a comma delimited (.csv) text file.

    (Barry and others, 1975; Stockwell, 2007)

    Person who carried out this activity:

    U.S. Geological Survey
    c/o David Foster
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543
    USA

    508-548-8700 x 2271 (voice)
    508-457-2310 (FAX)
    dfoster@usgs.gov

    Date: 2008 (process 2 of 2)
    A C-Shell script using 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 was then executed. All images were created with a horizontal scale of 40 traces per inch. The profiles contain 50 milliseconds of Two-Way Travel Time within an 8-inch vertical window, yielding 6.25 milliseconds per inch. Postscript images were converted to JPEG format using the UNIX ImageMagick (version 5.5.6).

    Software: Seismic Unix 4.1, ImageMagick 5.5.6

    Person who carried out this activity:

    David Foster
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543
    USA

    508-548-8700 x2271 (voice)
    508-457-2310 (FAX)
    dfoster@usgs.gov

  3. What similar or related data should the user be aware of?

    Foster, David S. , and Denny, Jane F. , 2009, Quaternary Geologic Framework of the St. Clair River between Michigan and Ontario, Canada: Open-File Report 2009-1137, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    Stockwell, John, 2007, Seismic Un*x: Center for Wave Phenomena - Colorado School of Mines, Golden, CO.

    Online Links:

    Barry, K.M., Cavers, D.A., and Kneale, C.W., 1975, Report on recommended standards for digital tape formats: Geophysics v. 40, no. 02, p. 344-352., Society of Exploration Geophysicists (SEG), Houston, TX.

    Online Links:

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

  2. How accurate are the geographic locations?

    Differential Global Positioning System (DGPS) navigation data were acquired with a Communications Systems International (CSI), Inc. LGBX Pro receiver and sent to Knudsen acquisition software, SounderSuite, where Chirp sub-bottom data with a peak frequency of 3.5 kHz were recorded in Society of Exploration Geophysicists Y (SEG-Y) format (Barry and others, 1975) with DGPS logged to the SEG-Y trace headers.

    DGPS accuracy is 1 to 3 meters, depending on the distance from a US Coast Guard coastal repeater station (<http://www.navcen.uscg.gov/>). DGPS accuracy is 1 to 3 meters, depending on the distance from a US Coast Guard coastal repeater station (<http://www.navcen.uscg.gov/>).

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    All acquired chirp seismic data were processed and JPEG images produced.

  5. How consistent are the relationships among the observations, including topology?

    Processed chirp seismic data were converted to JPEG format for ease of seismic trace display. Quality control was conducted during processing.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None
Use_Constraints:
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.

  1. Who distributes the data set? (Distributor 1 of 1)

    Jane Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543
    USA

    508-548-8700 x2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov

  2. What's the catalog number I need to order this data set?

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

    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.

  4. How can I download or order the data?

  5. What hardware or software do I need in order to use the data set?

    These JPEG data can be viewed with any image viewing software.

Who wrote the metadata?

Dates:
Last modified: 25-Jan-2011
Metadata author:
U.S. Geological Survey
c/o Jane F. Denny
Geologist
384 Woods Hole Road
Woods Hole, MA 02543
USA

508-548-8700 x2311 (voice)
508-457-2310 (FAX)
jdenny@usgs.gov

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:

Generated by mp version 2.8.25 on Tue Jan 25 17:09:38 2011