Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - Sidescan-sonar Tracklines

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• What does this data set describe?
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
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  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
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• 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?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
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Title:

Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - Sidescan-sonar Tracklines

Abstract:

Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped depression tilted toward the main fault on the east side of the lake. The U.S. Geological Survey, in cooperation with researchers from several universities, has been studying the sediments of Bear Lake since 1996. The general purpose of this effort is to reconstruct past limnological conditions and regional climate on a range of timescales, from hundreds of years to hundreds of thousands of years. This research relates to a variety of human concerns, including water usage in the Bear River basin. Past work has included several coring operations, a seismic-reflection survey, sediment-trap deployments, a barge-mounted drilling operation with the GLAD800 drill rig, and a variety of other studies. The objectives of the September, 2002 operations, preliminarily reported here, were (1) to compile a detailed bathymetric map of the lake using swath-mapping techniques, in order to provide baseline data for a variety of applications and studies, and (2) to complete a sidescan-sonar survey of the lake, providing a nearly complete acoustic image of the lake floor. Limited amounts of subbottom acoustic-reflection data (chirp) were also collected, along with samples of lake-floor sediments representative of different kinds of backscatter patterns. These surveys followed an earlier subbottom acoustic-reflection survey (1997), using boomer and 3.5 kHz systems (S. M. Colman, unpublished data).

1. How should this data set be cited?

   Denny, Jane F. , 2003, Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - Sidescan-sonar Tracklines: U.S. Geological Survey, Woods Hole, MA.

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -111.5

   East_Bounding_Coordinate: -111.17

   North_Bounding_Coordinate: 42.2

   South_Bounding_Coordinate: 41.08

3. What does it look like?

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

   Beginning_Date: 04-Sep-2002

   Ending_Date: 16-Sep-2002

   Currentness_Reference: Publication Date

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

   Geospatial_Data_Presentation_Form: digital vector data

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

      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • Complete chain

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

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000089992. Longitudes are given to the nearest 0.000089992. Latitude and longitude values are specified in decimal degrees.

      The horizontal datum used is WGS84.
      The ellipsoid used is WGS84.
      The semi-major axis of the ellipsoid used is 6378137.0000000.
      The flattening of the ellipsoid used is 1/298.26.
      

7. How does the data set describe geographic features?

   Sidescan-Sonar System: Trackline

   Shapefile attribute table (Source: ArcView 3.2)

   Shape

   internal ArcView 3.2 ID (Source: ArcView 3.2)

   ArcView 3.2

   Length

   ArcView 3.2 internal ID (Source: ESRI ArcView 3.2)

   ArcView 3.2

   ID

   ArcView 3.2 internal ID (Source: ArcView 3.2)

   ArcView 3.2

   Line

   Line Number (Source: SEG-Y header)

   Line Number

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

2. Who also contributed to the data set?

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

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

   508-457-2311 (voice)
   508-457-2310 (FAX)
   jdenny@usgs.gov
   

These data represent sidescan-sonar trackline navigation data during geophysical survey in Bear Lake, Utah-Idaho.

1. From what previous works were the data drawn?

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

   Date: 2003 (process 1 of 1)

   The sidescan-sonar navigation is received by the Wide Area Augmentation System (WAAS) GPS network, sent directly to the sidescan-sonar acquisition system from the Coastal Oceanographics, Inc. Hypack navigation system, and recorded in the QMIPS header of each file. The navigation is later extracted from the header, and formatted into a comma-delimited ArcView Ungenerate text format. The file is then imported into ArcView, and a vector line shapefile is generated. The line numbers for each trackline are stored in an ASCII file listing unique track ID and line number. This file is imported into ArcView 3.2 as a table. The file is then joined to the line shapefile by the unique track ID. The table for the trackline file is the editted, a new field created, the line number information written to this new field, the join removed, and the file saved. This permantely saves the line number with the corresponding trackline.

   Person who carried out this activity:
   

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

   508-457-2311 (voice)
   508-457-2310 (FAX)
   jdenny@usgs.gov
   

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

1. How well have the observations been checked?

2. How accurate are the geographic locations?

   WAAS (Wide Area Augmentation System) Navigation was used to acquire navigation information. WAAS is considered to have a horizontal accuracy of < 3 meters. The WAAS data were recorded in the header of the sidescan-sonar raw data. The sidescan-sonar tow-vehicle was towed close to the surface at a static height, adjacent to the vessel. WAAS locations were assumed for the sidescan-sonar tow-vehicle. The sidescan-soanr tow-vehicle was assumed to be navigated to an accuracy of +/- 5 meters.

3. How accurate are the heights or depths?

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

   Complete

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

   These navigation data have been stripped from the header of sidescan-sonar data. They have been quality checked by comparing these data to navigation data acquired during cruise operations.

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

Access_Constraints: None

Use_Constraints:

The U.S. Geological Survey must be referenced as the originator of the dataset in any future publications.

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

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

   508-457-2311 (voice)
   508-457-2310 (FAX)
   jdenny@usgs.gov
   

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

3. What legal disclaimers am I supposed to read?

   This publication was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data published on this CD-ROM have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and/or the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data, software, or related materials.

4. How can I download or order the data?

Dates:

Last modified: 19-Jan-2002
Last Reviewed: 2002

Metadata author:

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

508-457-2311 (voice)
508-457-2310 (FAX)
jdenny@usgs.gov

Metadata standard:

FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)