Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - Seismic Navigation: Start of Line

Frequently-anticipated questions:

• 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?
  1. Who are the originators of the data set?
  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?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• 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?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

Title:

Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - Seismic Navigation: Start of Line

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. , 2002, Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - Seismic Navigation: Start of Line: U.S. Geological Survey, Woods Hole, MA.

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -111.5

   East_Bounding_Coordinate: -111.2

   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):

      • point

   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.
      

      Vertical_Coordinate_System_Definition:

      Altitude_System_Definition:

      Altitude_Datum_Name: Assumed sea level

      Altitude_Resolution: 1

      Altitude_Distance_Units: Two-way travel time

      Altitude_Encoding_Method: Attribute values

      Depth_System_Definition:

      Depth_Datum_Name: Local surface

      Depth_Resolution: 1

      Depth_Distance_Units: Meters

      Depth_Encoding_Method: Attribute values

7. How does the data set describe geographic features?

   Seismic Shot Point Navigation

   Shapefile Attribute Table (Source: ArcView 3.2)

   Shape

   internal ArcView 3.2 ID (Source: ArcView 3.2)

   ArcView 3.2

   Lon

   X coordinate in Geographic Coordinate System (Source: Geographic Coordinate System)

   Range of values
   Minimum:	-111.5
   Maximum:	-111.17

   Lat

   y-Coordinate in Geographic Coordinate System (Source: Geographic Coordinate System)

   Range of values
   Minimum:	41.08
   Maximum:	42.2

   Line

   Line Number (Source: data set)

   Line Number

   Shot

   Shot Point Number (Source: data set)

   Shot Point Number

   UTMX

   X Coordinate; UTM, Zone 12 (Source: data set)

   Range of values
   Minimum:	450000
   Maximum:	480000

   UTMY

   Y-Coordinate; UTM, Zone 12 (Source: data set)

   Range of values
   Minimum:	4500000
   Maximum:	4700000

   Year

   Calendar Date (Source: Calendar)

   Calendar Date

   JD_HR_MIN_

   Time - Julian Day, Hour, Minute, Second (Source: Calendar Date)

   Calendar Date

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 the first shot point for each line of data acquired with various seismic-reflection systems utilized during U.S. Geological Survey geophysical research cruises.

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 seismic shot navigation is received by the differential GPS system (WAAS), sent directly to the seismic acquisition system, and recorded in the SEG-Y header of each file. The navigation is later extracted from the SEG-Y header, the first shot point is extracted, converted from its native UTM projection (zone 12, units meters, WGS84 datum) to Geographic Coordinate System, and formatted into a comma-delimited ASCII file. This file is imported into ArcView 3.2 as a table. The table is then converted into a point shapefile.

   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 chirp tow-vehicle was towed at the surface, next to the vessel. WAAS positioning was recorded in the SEGY header of the seismic data. Navigation of the seismic tow-vehicle is assumed to be +/- 3 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 seismic SEG-Y 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)