PAC_EXT - Extracted seabed data for the continental margin of the U.S. Pacific Coast (California, Oregon, Washington) from usSEABED (pac_ext.txt)

Frequently anticipated questions:

• What does this data set describe?
  1. How might 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 might this data set be cited?
   Reid, Jane A., Reid, Jamey M., Jenkins, Chris J., Zimmermann, Mark, Williams, S. Jeffress, and Field, Michael E., 2006, PAC_EXT - Extracted seabed data for the continental margin of the U.S. Pacific Coast (California, Oregon, Washington) from usSEABED (pac_ext.txt): Data Series 182, U.S. Geological Survey, Coastal and Marine Geology Program, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

   Online Links:

   • https://pubs.usgs.gov/ds/2006/182/data/pac_ext.zip
   • https://pubs.usgs.gov/ds/2006/182/data_cata.html
   • https://doi.org/10.3133/ds182

   This is part of the following larger work.
   Reid, Jane A., Reid, Jamey M., Jenkins, Chris J., Zimmermann, Mark, Williams, S. Jeffress, and Field, Michael E., 2006, usSEABED: Pacific Coast Offshore Surficial-Sediment Data Release: Data Series 182, U.S. Geological Survey, Coastal and Marine Geology Program, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

   Online Links:

   • https://doi.org/10.3133/ds182
   • https://pubs.usgs.gov/ds/2006/182/index.html

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -128.66600
   East_Bounding_Coordinate: -117.10170
   North_Bounding_Coordinate: 48.99883
   South_Bounding_Coordinate: 30.57000
   

3. What does it look like?

   https://pubs.usgs.gov/ds/2006/182/data/pac_ext.jpg (JPEG)

   Image map showing extent of data layer coverage

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

   Calendar_Date: 2006

   Currentness_Reference:

   publication date

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

   Geospatial_Data_Presentation_Form: comma-delimited text and vector digital 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):
      • Entity point (16486)
   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. The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.
      
7. How does the data set describe geographic features?

   pac_ext

   Shapefile Attribute Table (Source: ESRI)

   FID

   Internal feature number. (Source: ESRI) Sequential unique whole numbers that are automatically generated.

   Shape

   Feature geometry. (Source: ESRI) Coordinates defining the features.

   LATITUDE

   Latitude coordinate of sample location (Source: USGS) Location information in decimal degrees

   LONGITUDE

   Longitude coordinate of sample location (Source: USGS) Location information in decimal degrees

   WATERDEPTH

   Water depth of sample (Source: USGS) Water depth of sample in meters

   SAMPLETOP

   Measured subbottom depth information for each point sample or subsample (top) (Source: USGS) Subsample location information in meters

   SAMPLEBASE

   Measured subbottom depth information for each point sample or subsample (bottom) (Source: USGS) Subsample location information in meters

   SITENAME

   Survey or laboratory code for site (non-unique) (Source: USGS) Character string

   DATASETKEY

   Data set key (relational link) (Source: USGS) Unique sequential numeric key to SRC file

   SITEKEY

   Site key (relational link) (Source: dbSEABED MNEv program) Unique sequential numeric key to information about the same site in other usSEABED data files

   SAMPLEKEY

   Sample key (relational link) (Source: dbSEABED MNEv program) Unique sequential numeric key to information about the same sample or subsample in other usSEABED data files

   SAMPLER

   Equipment used to collect samples (Source: USGS) Character string containing name of device used to acquire sample

   DATATYPES

   Type of data that were used to derive values held in characterization (Source: USGS)

   Value	Definition
   ACU	Acoustic Properties
   CMP	Sediment Composition
   COL	Color
   GTC	Geotechnical Properties
   GRZ	Grain Size
   TXR	Texture
   TXG	Texture (Graphic)
   LTH	Lithology

   GRAVEL

   Gravel grainsize fraction (Source: Defined by original source)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	Percent
   Resolution:	1

   SAND

   Sand grainsize fraction (Source: Defined by original source)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	Percent
   Resolution:	1

   MUD

   Mud grainsize fraction (Source: Defined by original source)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	Percent
   Resolution:	1

   CLAY

   Clay grainsize fraction (Source: Defined by original source)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	Percent
   Resolution:	1

   GRAINSIZE

   Phi characteristic grainsize (moment mean or median) see Larger_Work_Citation (Source: USGS)

   Range of values
   Minimum:	-12
   Maximum:	12
   Units:	Phi
   Resolution:	0.1

   SORTING

   Phi grainsize dispersion; Moment measure standard deviation sorting only (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	6
   Units:	phi
   Resolution:	0.1

   SEABEDCLS

   Seabed class; (Facies) with the maximum fuzzy-membership value > 30%; see pac_fac.txt file (Source: USGS) Alpha characters

   CLSMSHP

   Class membership; fuzzy membership (%) of above Class (Facies) (Source: USGS)

   Range of values
   Minimum:	30
   Maximum:	100
   Units:	Fuzzy membership
   Resolution:	1

   FOLKCODE

   Grainsize classification (Source: Folk, Andrews, and Lewis, 1970)

   Value	Definition
   (g)M	Slightly gravelly mud
   (g)mS	Slightly gravelly muddy sand
   (g)sM	Slightly gravelly sandy mud
   (g)S	Slightly gravelly sand
   G	Gravel
   gM	Gravelly mud
   gmS	Gravelly muddy sand
   gS	Gravelly sand
   M	Mud
   mG	Muddy gravel
   mS	Muddy sand
   msG	Muddy sandy gravel
   S	Sand
   sG	Sandy gravel
   sM	Sandy mud
   H	Hard ground

   SHEPARDCOD

   modified Shepard code; grain size classification (Source: USGS)

   Value	Definition
   CLAYEY SILT	Sediment that is mostly silt with clay as the next most common component
   SANDY SILT	Sediment that is mostly silt with sand as the next most common component
   SAND SILT CLAY	Sediment with significant sand, silt, and clay
   SILTY CLAY	Sediment that is mostly clay with silt as the next most common component
   SAND	Sediment with greater than 80 percent in the 62 micron to 2 mm fraction
   SILTY SAND	Sediment that is mostly sand with silt (greater than 20 percent) as the next most common component
   SEDIMENT	Relative primary textural class
   CLAYEY SAND	Relative primary textural class
   CLAY	Relative primary textural class
   SANDY CLAY	Relative primary textural class
   SILT	Relative primary textural class
   GRAVELLY SEDIMENT	Sediment with greater than 10 percent gravel, but less than 50 percent
   GRAVEL	Sediment with nominal diameter coarser than 2mm
   SEDIMENT	Relative primary textural class

   ROCKMSHP

   Rock membership; fuzzy membership (%) reflecting percent exposure of rock (Source: dbSEABED processing software)

   Value	Definition
   -99	No data

   WEEDMSHP

   Weed membership; fuzzy membership reflecting abundance of seaweed and seagrass (Source: dbSEABED processing software MNEv and thesaurus)

   Value	Definition
   -99	No data

   CARBONATE

   Carbonate, including finest to coarsest sampled fractions (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	Percent
   Resolution:	1

   MUNSLCODE

   Munsell color code (Source: GSA Rock-Color Chart, 1991) Non-unique code based on HVC (Hue, Value, Chroma)

   ORGCARBON

   Organic carbon in the sample (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	Percent
   Resolution:	0.1

   LGSHEARSTR

   Undrained compressive shear strength, Log10 of KiloPascals (Source: Defined by original source)

   Value	Definition
   -99	No data

   ROUGHNESS

   A coded output representing the V:H of the roughness element with greatest aspect ratio (Source: dbSEABED processing software MNEv and thesaurus) Values expressed as (rounded) integer log2 of V and H in cm

   POROSITY

   Void volume (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	Unknown
   Units:	kPa
   Resolution:	1

   PWAVEVEL

   Compressional wave velocity (Source: dbSEABED processing software MNEv and thesaurus)

   Value	Definition
   -99	No data

   LGCRSHST

   Log Critical Shear Stress, Log10 of Tau in kPa, being the Shear Stress required to initiate easily observable erosion and transport, whether by traction or suspension (Source: USGS)

   Value	Definition
   -99	No data

   SAMPLEPHAS

   Sample Phase; records whether the results are for the whole, bulk sediment or just to some special part (Source: dbSEABED processing software) Character string output as a word-based description that may involve numerics. This field will need to be selected against when GIS mappings of the bulk sedient characters are being mapped. Only blank entries should be included in such a mapping.

   Entity_and_Attribute_Overview:

   Values of -99 for any field are indications that there was no data available.

   Entity_and_Attribute_Detail_Citation: See dbSEABED page in Larger_Work_Citation
   

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Jane A. Reid
   • Jamey M. Reid
   • Chris J. Jenkins
   • Mark Zimmermann
   • S. Jeffress Williams
   • Michael E. Field
2. Who also contributed to the data set?
   We thank the contributors of the data and the following interns for their assistance in data entry, coding, and testing, and (or) assistance with source metadata: K. Halimeda Kilbourne, Carolynn Box, Tara Kneeshaw, Jennifer Mendonca, April Villagomez, Monica Iglecia, and Adam Jackson.
3. To whom should users address questions about the data?
   Jane A. Reid

   U.S. Geological Survey

   Geologist

   Pacific Coastal and Marine Science Center

   Santa Cruz, CA
   

   USA

   831-427-4727 (voice)

   jareid@usgs.gov

   Contact_Instructions: email preferred
   

Why was the data set created?

How was the data set created?

1. From what previous works were the data drawn?

   Varies with source (source 1 of 1)

   Various, Unknown, See Data Sources page (https://pubs.usgs.gov/ds/2006/182/pac_sources.html and links therein, or the relationally linked file https://pubs.usgs.gov/ds/2006/182/data/pac_src.txt (PAC_SRC.txt), and links therein, within the data publication (see https://pubs.usgs.gov/ds/2006/182/index.html) for the specific sources and associated metadata.: Various publishers/originators, Various publication places.

   Other_Citation_Details:

   Over 300 sources, both published and unpublished, are used as the sources of information for usSEABED. Metadata for each source is given through the Data Sources page (https://pubs.usgs.gov/ds/2006/182/pac_sources.html) and relationally linked to the data through the file https://pubs.usgs.gov/ds/2006/182/data/pac_src.txt (PAC_SRC.txt). Sources include the U.S. Geological Survey (USGS), the U.S. Army Corps of Engineers (USACE), Minerals Management Service (MMS), National Oceanic and Atmospheric Administration (NOAA), the University of Washington, Seattle, Oregon State University, Corvallis, Universities of California, Berkeley, Los Angeles, and San Diego, University of Southern California, San Jose and Humboldt State Universities, Naval Postgraduate School, Virginia Institute of Marine Science (VIMS) and other educational institutions, the Maryland and New Jersey State Geological Surveys (MGS, NJGS), U.S. Navy, Southern California Coastal Water Research Project (SCCWRP), other local and regional consortia and authorities, NOAA's National Geophysical Data Center (NGDC), the Smithsonian Institution, and others.

   Type_of_Source_Media: Hard copy and digital
   Source_Contribution:

   Point locations, descriptions, and various analytical data (textural, granulometric, geochemical, geophysical, acoustic) on sediments, rock exposure, and benthos. Contributions vary with source.

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

   Date: 22-Dec-2005 (process 1 of 5)

   Source data may be digitized as necessary (typed or scanned in), with a visual inspection of digitized data to the source report and corrections as necessary, and are tested for completeness in Microsoft Excel as appropriate. Other digital data may be decoded using source-specific programs, downloaded via the web, or sent directly to the USGS or University of Colorado via email. Data are formatted into the dbSEABED Data Entry template (db9_DataEntry.xls, version 05/27/05) by hand, and tested using the dbSEABED relational database program (RDBi, version 01/05/2005) for correctness of formatting. For consistency, simple unit changes may be done. Data are compiled into source data resource files (DRF) and were processed through the dbSEABED data mining program (MNEv, version 12/18/2005) program, using the dbSEABED thesaurus (db9_dict.rtf, version 10/29/2005) and component set up file for U.S. waters (SET_ABUN.txt, version 07/20/2005). Data are iteratively reprocessed and corrected until noted errors are fixed, as recorded by the _RBDS.2fx and _MNE.DGN files. Data are exercised in a GIS for location tests and useability. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: Jane A. Reid

   Geologist

   USGS Pacific Coastal and Marine Science Center

   Santa Cruz, CA
   

   USA

   831.427.4727 (voice)

   jareid@usgs.gov

   Contact_Instructions: Email preferred
   

   Data sources produced in this process:

   • PAC_EXT.txt

   Date: 26-Apr-2018 (process 2 of 5)

   Keywords added to metadata support discovery in the USGS Coastal and Marine Geology Data Catalog. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: Alan O. Allwardt

   Contractor -- Information Specialist

   2885 Mission Street

   Santa Cruz, CA
   

   831-460-7551 (voice)

   831-427-4748 (FAX)

   aallwardt@usgs.gov

   Date: 04-Dec-2019 (process 3 of 5)

   Edits were made to bring the metadata up to current PCMSC standards including adding a doi# link, correcting typos, refining keywords, and using current access and distribution liability statements. Point of Contact and Metadata Contact information sections were changed to static PCMSC contact information. Users are advised to compare the metadata date of this file to any similar file to ensure they are using the most recent version. Person who carried out this activity:
   

   Susan A Cochran

   U.S. Geological Survey, Pacific Coastal and Marine Science Center

   2885 Mission St.

   Santa Cruz, CA
   

   United States

   831-460-7545 (voice)

   scochran@usgs.gov

   Date: 19-Oct-2020 (process 4 of 5)

   Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: VeeAnn A. Cross

   Marine Geologist

   384 Woods Hole Road

   Woods Hole, MA
   

   508-548-8700 x2251 (voice)

   508-457-2310 (FAX)

   vatnipp@usgs.gov

   Date: 16-May-2023 (process 5 of 5)

   Edits were made to correct spelling in author name. No data were changed. The metadata available from a harvester may supersede metadata bundled within a download file. Users are advised to compare the metadata date of this file to any similar file to ensure they are using the most recent version. (scochran@usgs.gov)

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?
   Accuracy of each attribute is dependent on the accuracy of the lineage data.
2. How accurate are the geographic locations?
   Locational accuracy is dependent on the accuracy of the navigational technique from the individual data sources and may vary widely (e.g., from 0.005km (differential GPS) in more recent surveys to greater than 2 km based on radar, Loran, or dead reckoning in older surveys.) Users of the data should use their own criteria for assessing the accuracy of the locations.
3. How accurate are the heights or depths?
   Locational accuracy is dependent on the accuracy of the navigational technique from the individual data sources. Users of the data should use their own criteria for assessing the accuracy of the locations.
4. Where are the gaps in the data? What is missing?
   Additional useable data may exist in this area; the authors appreciate any information and leads.
5. How consistent are the relationships among the observations, including topology?
   Data in the usSEABED data collection are based on the observations and analyses of others, filtered through a unifying and mining software. Each source report varies in type of information/data recorded and format. Only those observations that are recorded can be filtered and mined; only presence (not absences) of information can be noted.

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey

   Attn: Jane A. Reid

   Geologist

   2885 Mission Street

   Santa Cruz, CA
   

   USA

   831.427.4727 (voice)

   jareid@usgs.gov

   Contact_Instructions: Email preferred
   

2. What's the catalog number I need to order this data set? Downloadable Data: USGS Data Series 182 (downloadable through the web).
3. What legal disclaimers am I supposed to read?
   Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty..
4. How can I download or order the data?
   • Availability in digital form:

     Data format:	Text file containing data input to usSEABED. Fields are comma separated values. First record of file contains field names. in format comma-delimited text Size: 13.3
     Network links:	https://pubs.usgs.gov/ds/2006/182/data/pac_ext.txt https://pubs.usgs.gov/ds/2006/182/data_cata.html https://doi.org/10.3133/ds182

     Data format:

     The SHP file contains the geospatial data. The SHX file contains the index of the geospatial data. The DBF file contains the attribute data in dBASE format. The PRJ file contains the coordinate system information (optional). The AVL file contains the legend information (optional). The SBN and SBX files contain the spatial index of the geospatial data (optional). in format shapefile (version 2005) ESRI point shapefile

     Network links:

     https://pubs.usgs.gov/ds/2006/182/data/pac_ext.zip https://pubs.usgs.gov/ds/2006/182/data_cata.html https://doi.org/10.3133/ds182

   • Cost to order the data: None

5. What hardware or software do I need in order to use the data set?
   None; these data are provided as comma-delimited text files useable in most softwares. Additionally, these data are available in Environmental Systems Research Institute (ESRI) shapefile format. The user must have ArcGIS or ArcView 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing the data. A free data viewer, ArcExplorer, capable of displaying the data is available from ESRI at https://www.esri.com.

Who wrote the metadata?

Dates:

Last modified: 16-May-2023

Metadata author:

U.S. Geological Survey, Pacific Coastal and Marine Science Center

Attn: PCMSC Science Data Coordinator

2885 Mission Street

Santa Cruz, CA

US

831-427-4747 (voice)

pcmsc_data@usgs.gov

Metadata standard:

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