Seafloor character, 2-m-resolution grid--Offshore of Monterey, California

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?
   Erdey, Mercedes D., and Cochrane, Guy R., 2016, Seafloor character, 2-m-resolution grid--Offshore of Monterey, California: Data Series DS 781, U.S. Geological Survey, Reston, VA.

   Online Links:

   • https://doi.org/10.3133/ds781
   • https://cmgds.marine.usgs.gov/data/csmp/OffshoreMonterey/data_catalog_OffshoreMonterey.html

   This is part of the following larger work.
   Golden, Nadine E., 2015, California State Waters Map Series Data Catalog: Data Series DS 781, U.S. Geological Survey, Reston, VA.

   Online Links:

   • https://doi.org/10.3133/ds781

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -122.064886
   East_Bounding_Coordinate: -121.811775
   North_Bounding_Coordinate: 36.692799
   South_Bounding_Coordinate: 36.532722
   

3. What does it look like?

   https://www.sciencebase.gov/catalog/file/get/56cf5fc5e4b015c306ed183c?name=SeafloorCharacter_2m_OffshoreMonterey.jpg&allowOpen=true (JPEG)

   Seafloor character types of the Offshore of Monterey map area, classified from 2-m-resolution data.

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

   Beginning_Date: 1998

   Ending_Date: 2014

   Currentness_Reference:

   ground condition

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

   Geospatial_Data_Presentation_Form: GeoTiff
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      This is a Raster data set. It contains the following raster data types:
      • Dimensions 8201 x 10469 x 1, type Pixel
   2. What coordinate system is used to represent geographic features?
      The map projection used is NAD 1983 UTM Zone 10N.
      

      Projection parameters:

      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -123.0
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 500000.0
      False_Northing: 0.0
      

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 2.0
      Ordinates (y-coordinates) are specified to the nearest 2.0
      Planar coordinates are specified in Meter
      The horizontal datum used is NAD 1983.
      The ellipsoid used is GRS80.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
      

      Vertical_Coordinate_System_Definition:

      Altitude_System_Definition:

      Altitude_Datum_Name: North American Vertical Datum of 1988
      Altitude_Resolution: 2.0
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method: Attribute values
      

7. How does the data set describe geographic features?

   SeafloorCharacter_2m_OffshoreMonterey.tif.vat

   The shapefile attributes include VALUE - code for the seafloor character classes, COUNT - number of pixels, SLOPE - slope classes, DEPTH_ZONE - depth zones, SUBSTRATE - substrate classes, SUBST_DESC - short description of substrate classes, and FULL_DESC - detailed description of substrate classes. The shapefile can be added to any ESRI ArcMap project. (Source: ESRI)

   OID

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

   VALUE

   This seafloor-character class was produced using video-supervised maximum-likelihood classification of the bathymetry and backscatter (intensity of return) signals from sonar systems. Derivative roughness (rugosity) and backscatter intensity were used as variants in the classification. The resulting four substrate classes (I-IV) were divided into the Depth Zones (see Attribute: DEPTH_ZONE) by adding to the original grid value in increments of 10. Depth Zone 2, add 0 to grid value; and Depth Zone 3, add 10 to grid value. The resulting grid was further classified into Slope Classes (see Attribute: SLOPE) by adding to the classified raster values (including depth zones) in increments of 50. Slope Class 1, add 0 to grid value; Slope Class 2, add 50 to grid value; Slope Class 3, add 100 to grid value; and Slope Class 4, add 150 to grid value. (Source: ESRI)

   Range of values
   Minimum:	1
   Maximum:	123
   Units:	Integers 1 - 123 representing seafloor character classes.

   COUNT

   The number of pixels (2 m x 2 m size grid cell) represented in each seafloor class (see Attribute: VALUE). (Source: ESRI)

   Range of values
   Minimum:	80
   Maximum:	12559660
   Units:	each

   SLOPE

   The slope zones for the final seafloor-character map grid were identified on the basis of the smoothed bathymetry grid. The smoothing was done by applying focal statistics to the original bathymetry grid. The tool uses a moving window and calculates the mean value of the central pixel within a circular neighborhood of 20 m radius along the whole raster map. The resulting raster map represents a smoothed value highlighting overall trends and eliminates local varieties in the terrain (such as higher slopes along rock outcrops). Slope class values are: 1 (flat; 0 degrees to 5 degrees), 2 (sloping; 5 degrees to 30 degrees), or 3 (steeply sloping; 30 degrees to 60 degrees), 4 (vertical; 60 degrees to 90 degrees), or 5 (overhang; greater than 90 degrees). (Source: USGS)

   Range of values
   Minimum:	1
   Maximum:	2
   Units:	Integer value 1 or 2 representing slope class of 0-30 degrees as described above.

   DEPTH_ZONE

   The depth zones for the final seafloor-character map grid were identified on the basis of the smoothed bathymetry grid. The smoothing was done by applying focal statistics to the original bathymetry grid. The tool uses a moving window and calculates the mean value of the central pixel within a circular neighborhood of 20 m radius along the whole raster map. The resulting raster map represents a smoothed value highlighting overall trends and eliminates local varieties in the terrain (such as varying depths along rock outcrops). Depth Zone values are: Depth Zone 1, intertidal; Depth Zone 2, intertidal to 30 m; and Depth Zone 3, 30 to 100 m, Depth Zone 4, 100 to 200 m; and Depth Zone 5, deeper than 200 m (California Department of Fish and Game, 2008). (Source: USGS)

   Range of values
   Minimum:	2
   Maximum:	5
   Units:	Integer values 2-5 representing slope classes as described above.

   SUBSTRATE

   Coded values of the substrate classes. Class 1, Fine- to medium-grained smooth sediment; Class 2, Mixed smooth sediment and rock; Class 3, Rock and boulder, rugose; Class 4, Medium- to coarse- grained sediment; Class 5, Hard anthropogenic material (Source: USGS)

   Range of values
   Minimum:	1
   Maximum:	4
   Units:	Integer values 1-4 representing substrate classes as described above.

   SUBST_DESC

   Summary description of the four substrate classes coded by the attribute SUBSTRATE. Class 1, Fine- to medium-grained smooth sediment; Class 2, Mixed smooth sediment and rock; Class 3, Rock and boulder, rugose; Class 4, Medium to coarse grained (in scour depressions) (Source: USGS) Names are in text form, maximum length: 50

   FULL_DESC

   Detailed description of the four substrate classes coded by the attribute SUBSTRATE. Class 1, Low backscatter, low rugosity, typically mud to medium-grained sand, often rippled and/or burrowed; Class 2, Moderate to very high backscatter, low rugosity, typically coarse-grained sand, gravel, cobble and bedrock; Class 3, High backscatter, and high rugosity, typically boulder and rugose bedrock; Class 4, Very high backscatter, low rugosity; typically medium- to coarse-grained, with some shell hash in shallow depressions; Class 5, High backscatter, low rugosity; related to development by humans. (Source: USGS) Names are in text form, maximum length: 250

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Mercedes D. Erdey
   • Guy R. Cochrane
2. Who also contributed to the data set?
3. To whom should users address questions about the data?
   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

Why was the data set created?

How was the data set created?

1. From what previous works were the data drawn?

   bathymetry (source 1 of 4)

   Dartnell, Peter, and Kvitek, Rikk G., 2016, Bathymetry--Offshore of Monterey, California: Data Series DS 781, U.S. Geological Survey, Reston, VA.

   Online Links:

   • https://doi.org/10.5066/F70Z71C8

   Other_Citation_Details:

   See metadata for "Bathymetry_2m_OffshoreMonterey" and "Bathymetry_5m_OffshoreMonterey" in DS 781 for source data and postprocessing/reprocessing information.

   Type_of_Source_Media: digital files of gridded bathymetry data (ArcInfo GRID)
   Source_Contribution:

   Gridded bathymetry data at 2- and 5-meter resolution used to help with geologic and geomorphologic interpretations.

   backscatter (source 2 of 4)

   Dartnell, Peter, and Kvitek, Rikk G., 2016, Backscatter--Offshore of Monterey, California: Data Series DS 781, U.S. Geological Survey, Reston, VA.

   Online Links:

   • https://doi.org/10.5066/F70Z71C8

   Other_Citation_Details:

   See metadata for "Backscatter_5M_OffshoreMonterey" "Backscatter_7125_OffshoreMonterey" "Backscatter_8101_OffshoreMonterey" and "Backscatter_Swath_OffshoreMonterey" in DS 781 for amplitude source data and postprocessing/reprocessing information.

   Type_of_Source_Media:

   digital files of gridded amplitude (backscatter) data (ArcInfo GRID)

   Source_Contribution:

   Gridded amplitude data at 1- and 5-meter resolution used to help with geologic and geomorphologic interpretations.

   sediment (source 3 of 4)

   Reid, Jane A., Reid, Jamey M., Jenkins, Chris J., Zimmerman, Mark, Williams, S. Jeffress, and Field, Michael E., 2006, usSEABED—Pacific Coast (California, Oregon, Washington) offshore surficial-sediment data release: Data Series DS 182, U.S. Geological Survey, Menlo Park, CA.

   Online Links:

   • https://doi.org/10.3133/ds182

   Type_of_Source_Media: Esri project files, csv files
   Source_Contribution:

   seafloor sediment and rock samples used to interpret seafloor geology

   imagery (source 4 of 4)

   Golden, Nadine E., and Cochran, Guy R., 2013, California Seafloor Mapping Program video and photograph portal: data release DOI:10.5066/F7J1015K, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

   Online Links:

   • https://doi.org/10.5066/F7J1015K

   Type_of_Source_Media: seafloor video and photographs
   Source_Contribution:

   seafloor video and photographs used to interpret seafloor geology

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

   Date: 2016 (process 1 of 6)

   The seafloor-character map was produced using video-supervised maximum likelihood classification of the bathymetry and intensity of return from sonar systems. The classification was supervised using signatures defined by hand-drawn polygons located through sediment samples and video-observation ground truthing applying methodology described in Cochrane (2008), available at http://doc.nprb.org/web/research/research%20pubs/615_habitat_mapping_workshop/Individual%20Chapters%20High-Res/Ch13%20Cochrane.pdf.
   The two variants used in this classification were backscatter intensity and derivative rugosity. Rugosity measures terrain ruggedness as the variation in three-dimensional orientation of grid cells within a neighborhood. Vector analysis is used to calculate the dispersion of vectors normal (orthogonal) to grid cells within the specified neighborhood. This method effectively captures variability in slope and aspect into a single measure. Ruggedness values in the output raster map can range from 0 (no terrain variation) to 1 (complete terrain variation). The calculation was performed using the Terrain Ruggedness (VRM) tool. Bathymetry data were collected at two different resolutions: at 2-m resolution, down to approximately 90-m water depth (1998-2012 CSUMB and MBARI data); and at 5-m resolution, in the deeper areas (1998-2012 MBARI data). The final resolution of the seafloor-character map is determined by the resolution of both the backscatter and bathymetry datasets; therefore, separate seafloor-character maps were generated to retain the maximum resolution of the source data.
   Classes I, II and III values were delineated using multivariate analysis. Class IV values were determined on the basis of visual characteristics using both bathymetry and backscatter (slight depression in the seafloor, very high backscatter return). The resulting map (gridded at 2 m) was cleaned by hand to remove data-collection artifacts (for example trackline nadir). Editing was performed in Photoshop, with which individual pixels were selected and values adjusted to remove noise. Selection occurred without antialiasing, and the resulting grid was identical but for the edited pixels. The four seafloor classes were then colored to indicate which of the five California MLPA depth zones they are located in: Depth Zone 2 (intertidal to 30 m), Depth Zone 3 (30 to 100 m), Depth Zone 4 (100 to 200 m), or Depth Zone 5 (deeper than 200 m). These were further subdivided into one of the following slope classes: Slope Class 1 (0 degrees - 5 degrees; flat), or Slope Class 2 (5 degrees - 30 degrees; sloping). Depth Zone 1 (intertidal), Slope Class 3 (30 degrees to 60 degrees; steeply sloping), Slope Class 4 (60 degrees - 90 degrees; vertical), or Slope Class 5 (greater than 90 degrees; overhang) are not present in the region covered by the 2-m-resolution grid for the Offshore of Monterey map area.

   Date: 05-Oct-2017 (process 2 of 6)

   Keywords section of metadata optimized for discovery in 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: 26-Apr-2018 (process 3 of 6)

   Added keywords from Coastal and Marine Ecological Classification Standard (CMECS) to metadata. 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: 19-Oct-2020 (process 4 of 6)

   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: 14-Oct-2021 (process 5 of 6)

   Performed minor edits to the metadata to correct typos. No data were changed Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: Susan A. Cochran

   Geologist

   2885 Mission Street

   Santa Cruz, CA
   

   831-460-7545 (voice)

   scochran@usgs.gov

   Date: 20-May-2022 (process 6 of 6)

   Edits were made to bring the metadata up to current PCMSC standards including standardizing authors' names, 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. 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. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: Susan A. Cochran

   Geologist

   2885 Mission Street

   Santa Cruz, CA
   

   831-460-7545 (voice)

   scochran@usgs.gov

3. What similar or related data should the user be aware of?
   Johnson, S.Y., Dartnell, P., Hartwell, S.R., Cochrane, G.R., Golden, N.E., Watt, J.T., Davenport, C.W., Kvitek, R.G., Erdey, M.D., Krisgman, L.M., Sliter, R.W., and Maier, K.L., 2016, California State Waters Map Series--Offshore of Monterey, California: Open-File Report 2016-1110, U.S. Geological Survey, Reston, VA.

   Online Links:

   • https://doi.org/10.3133/ofr20161110

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?
   Pixel resolution 2 m.
2. How accurate are the geographic locations?
   Positional information reflects the position of the camera and was collected using a still photo camera, WAAS-enabled GSP unit, recording at between 1 to 2 nm. DGPS (WAAS) accuracy for position is less than 3 meters. (From Garmin GPSMAP 76C/76CS Specifications, M01-10108-00, Rev0304, (<http://www8.garmin.com/specs/GPSMAP76C_76CSspec.pdf>).
3. How accurate are the heights or depths?
   
4. Where are the gaps in the data? What is missing?
   Total coverage for the survey area is 100 percent. Survey area is defined by coverage of both the multibeam bathymetry and backscatter datasets.
5. How consistent are the relationships among the observations, including topology?
   Classification was done on the basis of training samples delineated by interpreter. The classification was performed using mathematical algorithms then hand-edited by the interpreter to remove noise.

How can someone get a copy of the data set?

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

   345 Middlefield Rd

   Menlo Park, CA
   

   USA

   (650) 329-4309 (voice)
2. What's the catalog number I need to order this data set?
3. What legal disclaimers am I supposed to read?
   These databases, identified as seafloor character maps of the Offshore of Monterey map area, California, have been approved for release and publication by the U.S. Geological Survey (USGS). Although these databases have been subjected to rigorous review and are substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use. Although these data have been processed successfully on a computer system at 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. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. These data are not intended for navigational use.
4. How can I download or order the data?
   • Availability in digital form:

     Data format:	The .zip file for the TIFF image includes the image (.tif), the world registration file (.tfw), and FGDC-compliant metadata for the Seafloor Character 2-m-resolution data layer of Offshore of Monterey map area, California. in format TIFF (version ArcMap (version 10.0, ESRI , 2011)) Raster data layer is registered TIFF image in the UTM Zone 10 coordinate system with datum WGS84. Size: 1.8
     Network links:	https://www.sciencebase.gov/catalog/file/get/56d0c74de4b015c306ee9b22 https://doi.org/10.5066/F70Z71C8 https://pubs.usgs.gov/ds/781/

   • Cost to order the data: none

5. What hardware or software do I need in order to use the data set?
   The downloadable data file has been compressed with the "zip" command and can be unzipped with Winzip (or other tool) on Windows systems. To utilize these data, the user must have software capable of uncompressing the WinZip file and importing and viewing an Esri ArcMap TIFF. Users should download the ArcGIS Project File, OffshoreMontereyGIS.mxd.zip, a compressed (with the "zip" command) version of the ArcMap document (.mxd) that has all the data layers loaded in the table of contents for "Offshore of Monterey map area" and has all the data symbolized as on the data release map sheets. Download and save this ArcGIS project file, including all data layers, to the directory the user has created for this GIS.

Who wrote the metadata?

Dates:

Last modified: 20-May-2022

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)