These data were collected under a cooperative agreement with the Massachusetts Office of Coastal Zone Management (CZM) and the U.S. Geological Survey (USGS), Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center (WHCMSC). Initiated in 2003, the primary objective of this program is to develop regional geologic framework information for the management of coastal and marine resources. Accurate data and maps of sea-floor geology are important first steps toward protecting fish habitat, delineating marine resources, and assessing environmental changes due to natural or human impacts. The project is focused on the inshore waters (5-30 m deep) of Massachusetts between the New Hampshire border and Cape Cod Bay. Data collected for the mapping cooperative have been released in a series of USGS Open-File Reports (http://woodshole.er.usgs.gov/project-pages/coastal_mass/). This is the spatial dataset for the Red Brook Harbor survey area within Buzzards Bay, Massachusetts. These data are the results of a high-resolution geophysical (bathymetry, backscatter intensity, and seismic reflection) and ground validation (sediment samples and bottom photographs) survey, conducted in 2009.
In addition to inclusion within the USGS-CZM geologic mapping effort, these Red Brook Harbor data will be used to assess the shallow-water mapping capability of the geophysical systems deployed for this project, with an emphasis on identifying resolution benchmarks for the interferometric sonar system. (http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2009-018-FA)
JPEG images of each seismic profile were generated in order to incorporate images of the seismic profiles into Geographic Information System (GIS) projects and data archives utilizing HTML. The JPEG images represent approximately 240 km of Knudsen 3202 chirp seismic-reflection data collected by the U.S. Geological Survey during Woods Hole Science Center cruise 09018 offshore of Massachusetts within Red Brook Harbor. Each profile image is hotlinked to its corresponding trackline navigation contained within the ESRI polyline shapefile 'RB_SeismicTracklines.shp'. Even 500 shot index markers along the top of the JPEG images correlate to the positions of 500 shot intervals within the ESRI point shapefile 'RB_SeismicShot_500.shp'.
Theme_Keyword_Thesaurus:None Theme_Keyword:U.S. Geological Survey Theme_Keyword:USGS Theme_Keyword:Coastal and Marine Geology Program Theme_Keyword:CMGP Theme_Keyword:Woods Hole Coastal and Marine Science Center Theme_Keyword:WHCMSC Theme_Keyword:Seafloor Theme_Keyword:Marine Geology Theme_Keyword:WHCMSC field activity serial number 09018 Theme_Keyword:WHCMSC field activity 2009-018-FA Theme_Keyword:seismic reflection Theme_Keyword:subbottom Theme_Keyword:seismic profile Theme_Keyword:JPEG Theme_Keyword:image Theme_Keyword:chirp Theme_Keyword:Knudsen Theme_Keyword:3202 Theme_Keyword:R/V Rafael
Place_Keyword_Thesaurus:None Place_Keyword:North America Place_Keyword:United States Place_Keyword:Atlantic Ocean Place_Keyword:Massachusetts Place_Keyword:Cape Cod Place_Keyword:Buzzards Bay Place_Keyword:Red Brook Harbor
Processed seismic data were converted to JPEG format for ease of seismic trace display. Quality control was conducted during processing. Changes in water depth, bottom type, and acquisition parameters during the survey caused significant variability in seismic trace amplitudes and subsurface penetration. Profiles in shallow water areas near the inner harbor experienced the most detrimental effects. Data quality generally improved as the survey progressed into the relatively deeper water of the outer harbor.
Differential Global Positioning System (DGPS) navigation data were acquired with a Communications Systems International (CSI), Inc. LGBX Pro receiver. Navigation data were sent to the Knudsen SounderSuite acquisition application, which logged the coordinates to individual trace headers in the Society of Exploration Geophysicists Y (SEG-Y) Revision 1 format (Norris and Faichney, 2002). A 2 m horizontal offset between the seismic transducers and the DGPS receiver was not accounted for during data acquisition, and resulting positional accuracy is assumed to be better than 10 m.
The source information was incomplete and had to be modified to meet the standard. Assumed to be USGS.
Publication_Date:unknown Title:Information unavailable from original metadata.
Type_of_Source_Media:Information unavailable from original metadata. Source_Time_Period_of_Content:
Information unavailable from original metadata. Assumed to be ground condition.
Source_Citation_Abbreviation:Information unavailable from original metadata. Source_Contribution:
Chirp seismic data were collected using a dual frequency (3.5 and 200 kHz) Knudsen Engineering Limited (KEL) Chirp 3202 system with transducers mounted on a rigid pole on the starboard side of the R/V Rafael of Woods Hole, MA. Knudsen SounderSuite seismic acquisition software was used to control the Chirp 3202 system, digitally log trace data in the Society of Exploration Geophysicists Y (SEG-Y) Revision 1 format (Norris and Faichney), and record DGPS navigation coordinates to the SEG-Y trace headers in arc seconds. The transducer draft was 0.5 m below the water surface, and the draft offset was accounted for during data acquisition. Navigation coordinates and water depths from the 200-kHz channel were logged together in ASCII formatted files for each survey line. During Julian days 271 - 287 data were acquired at a peak frequency of 3.5 kHz, a 0.25 or 0.2 second fire rate (4 or 5 shots per second), a 38 microsecond sample interval, and record lengths between 26 and 130 milliseconds. During Julian days 288 - 296 data were acquired at a peak frequency of 5.0 kHz, a .25 second fire rate, a 36 microsecond sample interval, and a 66 millisecond record length. A total of 240 km of seismic data were collected.
An executable C-shell script called on SIOSEIS (version 2007.8) to 1) mute water column portions of Knudsen 3202 seismic traces using the water depths recorded in the 200kHz channel; 2)apply gain and automatic gain control functions to the traces; and 3) write the resulting traces to new "mute_gain" SEG-Y files, which were used for creation of JPEG browse images and digital interpretation.
An executable C-Shell script called on Seismic Unix (version 4.1) to read the SEG-Y files and plot the data as 8-bit gray scale Postscript files. All images were created with a horizontal scale of 100 traces per inch. The profiles contain 50 milliseconds of Two-Way Travel Time within an 12-inch vertical window, yielding 4.2 milliseconds per inch. Postscript images were converted to JPEG format using ImageMagick (version 5.5.6).
Edits to the metadata were made to fix any errors that MP v 2.9.32 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.). Fixed URL in abstract. The source information was incomplete and had to be modified to meet the standard. The link to the data in the Distribution_Information section had to be fixed. 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.
Contact_Organization:U.S. Geological Survey Contact_Person:VeeAnn A. Cross
Resource_Description:Downloadable Data Distribution_Liability:
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.
Zip compressed JPEG images of processed Knudsen 3202 seismic-reflection profiles and associated metadata.
File_Decompression_Technique:Use WinZip or pkUnzip Transfer_Size:61.0
The metadata contact email address is a generic address in the event the metadata contact is no longer with the USGS or the email is otherwise invalid.
Metadata_Standard_Name:FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version:FGDC-STD-001-1998 Metadata_Time_Convention:local time Metadata_Access_Constraints:None Metadata_Use_Constraints:None
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/open_file_report/ofr2010-1091/RB_SeismicProfiles.jpg.html>
Generated by mp version 2.9.50 on Tue Nov 16 10:06:40 2021