Station locations and grain-size analysis of surficial sediment samples collected on the continental shelf, Gulf of the Farallones, during cruise F2-89-NC, January 1989

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?

What does this data set describe?

1. How should this data set be cited?

   Maher, Norman M. , Karl, Herman A. , Chin, John L. , and Schwab, William C. , 1991, Station locations and grain-size analysis of surficial sediment samples collected on the continental shelf, Gulf of the Farallones, during cruise F2-89-NC, January 1989: Open-file report 91-375A, U.S. Geological Survey, Menlo Park, CA.

   Online Links:

   • <http://pubs.er.usgs.gov/pubs/ofr/ofr91375A>

   Other_Citation_Details:

   Data from USGS cruise F289NC (<http://walrus.wr.usgs.gov/infobank/f/f289nc/html/f-2-89-nc.meta.html>).

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -123.38916

   East_Bounding_Coordinate: -122.54769

   North_Bounding_Coordinate: 38.06244

   South_Bounding_Coordinate: 37.42068

3. What does it look like?

   OFR_91_375A (JPG)

   Screen grab of GIS-produced sample distribution, with bathymetry and land for reference.

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

   Beginning_Date: 22-Jan-1989

   Ending_Date: 28-Jan-1989

   Currentness_Reference: Publication date

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

   Geospatial_Data_Presentation_Form: Paper

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 (266)

   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 0.00001. Longitudes are given to the nearest 0.00001. Latitude and longitude values are specified in Decimal degrees.

7. How does the data set describe geographic features?

   Point

   SDTS point (Source: Source report)

   Sample number

   Sample number (Source: US Geological Survey)

   Alpha numeric number based on cruise and core information

   Water depth

   Depth of water at sample site (Source: Source report)

   Range of values
   Minimum:	22
   Maximum:	119
   Units:	Meters
   Resolution:	1.0

   Gravel

   Gravel (Source: Wentworth, 1932)

   Range of values
   Minimum:	0
   Maximum:	81.27
   Units:	Percent
   Resolution:	0.1

   Sand

   Sand (Source: Wentworth 1932)

   Range of values
   Minimum:	0
   Maximum:	99.86
   Units:	Percent
   Resolution:	0.1

   Silt

   Silt (Source: Wentworth 1932)

   Range of values
   Minimum:	0.5
   Maximum:	87.78
   Units:	Percent
   Resolution:	0.01

   Clay

   Clay (Source: Wentworth 1932)

   Range of values
   Minimum:	0
   Maximum:	5.16
   Units:	Percent
   Resolution:	0.01

   Mud

   Mud (Source: Wentworth 1932)

   Range of values
   Minimum:	0
   Maximum:	92.54
   Units:	Percent
   Resolution:	0.01

   Median

   Median of grain-size distribution (Source: Source report)

   Range of values
   Minimum:	-1
   Maximum:	4.93
   Units:	Phi
   Resolution:	0.01

   Mean

   First moment: Mean of grain-size distribution (Source: Source report)

   Range of values
   Minimum:	0.73
   Maximum:	5.33
   Units:	Phi
   Resolution:	0.01

   Sorting

   Second moment: Standard deviation of grain-size distribution (Source: Source report)

   Range of values
   Minimum:	0.4
   Maximum:	2.5
   Units:	Phi
   Resolution:	0.01

   Skewness

   Third moment: Skewness of grain-size distribution (Source: Source report)

   Range of values
   Minimum:	-1.82
   Maximum:	12.82
   Units:	Unitless
   Resolution:	0.01

   Kurtosis

   Fourth moment: Kurtosis of grain-size distribution (Source: Source report)

   Range of values
   Minimum:	2.67
   Maximum:	233.72
   Units:	Unitless
   Resolution:	0.01

   Mean

   Mean of grain-size distribution (Source: Folk, 1968)

   Range of values
   Minimum:	-0.83
   Maximum:	5.22
   Units:	Phi
   Resolution:	0.01

   Sorting

   Standard deviation about the grain size mean (Source: Folk, 1968)

   Range of values
   Minimum:	0.19
   Maximum:	2.16
   Units:	Phi
   Resolution:	0.01

   Skewness

   Skewness of grain-size distribution (Source: Folk, 1968)

   Range of values
   Minimum:	-0.68
   Maximum:	1.0
   Units:	Unitless
   Resolution:	0.01

   Kurtosis

   Kurtosis of grain-size distribution (Source: Folk, 1968)

   Range of values
   Minimum:	0.48
   Maximum:	30.51
   Units:	Phi
   Resolution:	0.01

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Norman M. Maher
   • Herman A. Karl
   • John L. Chin
   • William C. Schwab

2. Who also contributed to the data set?

   The authors and others at the USGS for collection and analysis of data. For usSEABED, digitization and formatting: K. Halimeda Kilbourne and Jane Reid (USGS); Formatting corrections: Jane Reid (USGS) and Chris Jenkins (University of Colorado)

3. To whom should users address questions about the data?
   U.S. Geological Survey
   c/o John L. Chin
   USGS Coastal and Marine Geology
   Menlo Park, CA 94025
   

   650-329-5270 (voice)
   jchin@usgs.gov
   

Why was the data set created?

This investigation, the first of several planned adjacent to major population centers, was designed to establish a good scientific data base on a segment of continental shelf adjacent to the San Francisco Bay area so as to evaluate and monitor human impact on the marine environment. "

How was the data set created?

1. From what previous works were the data drawn?

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

   Date: 1991 (process 1 of 1)

   Please see the report for a detailed description of the sediment processing.

   Person who carried out this activity:
   

   U.S. Geological Survey
   c/o Michael Torresan
   USGS Coastal and Marine Geology
   Menlo Park, CA 94025
   

   650-329-5493 (voice)
   mtorresan@usgs.gov
   

   Data sources produced in this process:

   • OFR_91_375A

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?

   Detailed information is available in the report. For usSEABED, data were digitized, visually compared to the source and corrected. Where appropriate, data were tested for completeness using MS Excel. Locations checked using GIS.

2. How accurate are the geographic locations?

   Navigation by three systems: GPS, LORAN-C, and a shore-based transponder net. Positional accuracy varied from about 100 m using GPS and LORAN-C to a few meters using the shore-based transponder net.

3. How accurate are the heights or depths?

   Water depth determination probably by 3.5 kHz profiling systems. Subsample depths given as nearest centimeter.

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

   No estimate made for original data. For inclusion into usSEABED, all textural data in the report were included.

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

   Data fall within normal ranges for the given parameters.

How can someone get a copy of the data set?

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

Access_Constraints:

None. Paper copy of report is available through the USGS, and is also available online.

Use_Constraints: Cite the U.S. Geological Survey as the originators of the data.

1. Who distributes the data set? (Distributor 1 of 1)
   United States Geological Survey
   USGS Information Services
   Denver, CO 80225
   

   1-800-ASK-USGS (voice)
   

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

   Open file report 91-375A

3. What legal disclaimers am I supposed to read?

   Although this dataset has been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data. Users of the data should be aware of limitations of the data due to possible imprecision due to navigational inaccuracies and limitations of the statistical data.

4. How can I download or order the data?
   • Availability in non-digital form:

     Report is available through the USGS; scanned images are also available online at: <http://pubs.er.usgs.gov/pubs/ofr/ofr91-375A>

   • Cost to order the data: Unknown

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

   Plug-in not required, but best viewed with downloadable program DjVu at <http://www.lizardtech.com/download/dl_options.php?page=plugins>

Who wrote the metadata?

Dates:

Last modified: 2005

Metadata author:

U.S. Geological Survey
c/o Jane A. Reid
Geologist
400 Natural Bridges Drive
Santa Cruz, CA 95060

831-427-4727 (voice)
jareid@usgs.gov

Contact_Instructions: Email preferred

Metadata standard:

CSDGM Version 2 (FGDC-STD-001-1998)