Historical coastal bluff edge positions at Barter Island, Alaska for the years spanning 1950 to 2020

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Frequently anticipated questions:

What does this data set describe?

Title:
Historical coastal bluff edge positions at Barter Island, Alaska for the years spanning 1950 to 2020
Abstract:
This dataset includes one vector shapefile delineating the position of the top edge of the coastal permafrost bluffs at Barter Island, Alaska spanning seven decades, between the years of 1950 and 2020. Bluff-edge positions delineated from a combination of aerial photography, declassified satellite photography, and very-high resolution satellite imagery can be used to quantify the movement of the bluff edge through time. These data were used to calculate rates of change every 10 meters alongshore using the Digital Shoreline Analysis System (DSAS) version 5.0. DSAS uses a measurement baseline method to calculate rate-of-change statistics. Transects are cast from the reference baseline to intersect each bluff edge vector, establishing measurement points used to calculate bluff change rates.
Supplemental_Information:
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the dataset in nonproprietary form, as well as in Esri format, this metadata file may include some Esri-specific terminology.
  1. How might this data set be cited?
    Gibbs, Ann E., 20201204, Historical coastal bluff edge positions at Barter Island, Alaska for the years spanning 1950 to 2020: data release DOI: 10.5066/P9CRBC5I, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

    Online Links:

    This is part of the following larger work.

    Gibbs, Ann E., Jones, Benjamin M., and Richmond, Bruce M., 2020, A GIS compilation of vector shorelines and coastal bluff edge positions, and associated rate-of-change data for Barter Island, Alaska: data release DOI:10.5066/P9CRBC5I, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -143.798211601
    East_Bounding_Coordinate: -143.369936039
    North_Bounding_Coordinate: 70.151990928
    South_Bounding_Coordinate: 70.083358162
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 02-Aug-1950
    Ending_Date: 10-Jul-2020
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Vector Digital Data Set (Polyline)
  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):
      • String (491)
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 7
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -141.0
      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 0.6096
      Ordinates (y-coordinates) are specified to the nearest 0.6096
      Planar coordinates are specified in Meter
      The horizontal datum used is D_North_American_1983.
      The ellipsoid used is GRS_1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.
  7. How does the data set describe geographic features?
    Attribute Table
    Table containing attribute information associated with the data set. (Source: Producer defined)
    Date_
    Date on which the source imagery for the digitized feature was collected in format MM/DD/YYYY. (Source: Producer defined.) Unknown
    Year_
    Year in which the source imagery for the digitized feature was collected. (Source: Producer defined.)
    Range of values
    Minimum:1950
    Maximum:2020
    Units:Years
    UNCY
    total horizontal position uncertainty, in meters. Actual position of the feature is within the range of this value. The uncertainty was determined by equation 1 in Gibbs and Richmond (2015). (Source: Producer defined.)
    Range of values
    Minimum:0.2
    Maximum:5.1
    Units:Meters
    Feature
    Feature digitized (Source: Producer defined)
    ValueDefinition
    Gully fillAn arbitrarily drawn line segment connecting two points that approximates a continuous bluff edge at locations where a gully incises landward into the bluff.
    Top of bluffTop edge of coastal bluff
    Source
    Identifies the source of the map or imagery from which the bluff edges in this dataset were digitized. (Source: Producer defined)
    ValueDefinition
    AHAP, Color infrared photographyAlaska High-altitude Aerial Photography, color infrared photographs
    CORONA, Panchromatic satellite photographyDeclassified CORONA satellite, panchromatic photography
    Fairbanks Fodar, Natural color aerial photographyOrthorectified, natural color aerial photo mosaics generated by Fairbanks Fodar using Structure from Motion (SfM)photogrammetry
    Hexagon, Panchromatic satellite photographyDeclassified Hexagon satellite, panchromatic photography
    Maxar IKONOS, Panchromatic satellite imageryMaxar IKONOS satellite, panchromatic imagery
    Maxar Quickbird, Panchromatic satellite imageryMaxar Quickbird satellite, panchromatic imagery
    Maxar WV01, Panchromatic satellite imageryMaxar Worldview 1 satellite, panchromatic imagery
    Maxar WV02, Panchromatic satellite imageryMaxar Worldview 2 satellite, panchromatic imagery
    Maxar WV02, Pansharpened multispectral satellite *Maxar Worldview 2 satellite, pansharpened multispectral satellite imagery
    Maxar WV02, Pansharpened natural color satellite imageryMaxar Worldview 2 satellite, pansharpened natural color satellite imagery
    USGS, Panchromatic aerial photographyUSGS, panchromatic single frame aerial photography
    Entity_and_Attribute_Overview:
    The entity and attribute information provided here describes the tabular data associated with the data set. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields/table entries of the data set.
    Entity_and_Attribute_Detail_Citation:
    The entity and attribute information were generated by the individual and/or agency identified as the originator of the data set. Please review the rest of the metadata record for additional details and information.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Ann E. Gibbs
  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

    831-427-4747 (voice)
    pcmsc_data@usgs.gov

Why was the data set created?

These data are part of a series of data quantifying rates and patterns of shoreline change and coastal permafrost bluff retreat from 1947 to 2020 at Barter Island. Alaska.

How was the data set created?

  1. From what previous works were the data drawn?
    Aerial photographs (source 1 of 6)
    U.S. Geological Survey, 19790713, Aerial Photos: Single Frame Aerial Photography Aerial Photography, U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota.

    Online Links:

    Type_of_Source_Media: Digital Resources
    Source_Contribution:
    Aerial photographs were used to delineate the top edge of the bluff and instantaneous land-water interface shoreline.
    Aerial photographs (source 2 of 6)
    U.S. Geological Survey, 19790713, Aerial Photos: Single Frame Aerial Photography Aerial Photography, U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota.

    Online Links:

    Type_of_Source_Media: Digital Resources
    Source_Contribution:
    Aerial photographs were used to delineate the top edge of the bluff and instantaneous land-water interface shoreline.
    CORONA satellite photograph (source 3 of 6)
    U.S. Geological Survey, 19690725, DECLASSIFIED SATELLITE PHOTOGRAPHY: DS1107-1028AA055: U.S. Geological Survey, Sioux Falls, South Dakota.

    Online Links:

    Type_of_Source_Media: Digital Resources
    Source_Contribution:
    The CORONA satellite photograph was used to delineate the top edge of the bluff and instantaneous land-water interface shoreline.
    Hexagon satellite photograph (source 4 of 6)
    U.S. Geological Survey, 2015, Declassified Satellite Imagery 3: U.S. Geological Survey, Sioux Falls, South Dakota.

    Online Links:

    Type_of_Source_Media: Digital Resources
    Source_Contribution:
    The Hexagon satellite photograph was used to delineate the top edge of the bluff and instantaneous land-water interface shoreline.
    Maxar satellite imagery (source 5 of 6)
    Maxar, Unpublished material, IKONOS, Quickbird, Worldview 1, and Worldview 2 satellite images: Unpublished data, Unpublished data.

    Online Links:

    Type_of_Source_Media: Digital Resources
    Source_Contribution:
    Maxar satellite images were used to delineate the top edge of the bluff and instantaneous land-water interface shoreline. Images were acquired under the NextView licensing agreement which restricts image data use and distribution.
    Fodar imagery (source 6 of 6)
    Gibbs, Ann E., Nolan, Matt, and Snyder, Alexander G., 20190226, Orthophotomosaics, elevation point clouds, digital surface elevation models and supporting data from the north coast of Barter Island, Alaska: U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

    Online Links:

    Other_Citation_Details:
    Gibbs, A.E., Nolan, M., and Snyder, A.G., 2019, Orthophotomosaics, elevation point clouds, digital surface elevation models and supporting data from the north coast of Barter Island, Alaska: U.S. Geological Survey data release, https://doi.org/10.5066/P9964TKX
    Type_of_Source_Media: Digital Resources
    Source_Contribution:
    Fodar imagery was used to delineate the top edge of the bluff and instantaneous land-water interface shoreline.
  2. How were the data generated, processed, and modified?
    Date: 2020 (process 1 of 1)
    Bluff edge positions were delineated from a combination of historical maps, aerial photography, declassified satellite photography, and very-high resolution satellite imagery spanning a 70-year period between 1950 and 2020. Spatial resolution of the datasets ranged from 0.08 to 3.9 m. Images were georeferenced and rectified using map coordinates, ground survey points, and/or image-to-image correlation of photo-identifiable ground features. A total root-mean-square rectification error was determined for each dataset based on the residuals. Vectors were digitized in a GIS from all data sources using standard editing tools in ArcMap 10.7 using criteria described in Gibbs and Richmond (2015) and Gibbs and others (2019). A total horizontal position uncertainty of the feature was determined as the quadrature sum of all uncertainties, including the georeferencing, digitizing, and RMSE on image rectification. Long- and short-term bluff change rates were calculated every 10 meters alongshore using the Digital Shoreline Analysis System 5.0 (Himmelstoss and others, 2018). Linear regression and weighted linear regression methods were employed for long-term change rate calculations and an end-point rate method was employed for annual and semi-annual change rate calculations. Additional details on methodology and uncertainty estimates can be found in Gibbs and Richmond (2015) and Himmelstoss and others (2018).
  3. What similar or related data should the user be aware of?
    Gibbs, Ann E., and Richmond, Bruce M., 2015, National assessment of shoreline change—Historical shoreline change along the north coast of Alaska, U.S.–Canadian border to Icy Cape.

    Online Links:

    Other_Citation_Details:
    Gibbs, A.E., and Richmond, B.M., 2015, National assessment of shoreline change—Historical shoreline change along the north coast of Alaska, U.S.–Canadian border to Icy Cape: U.S. Geological Survey Open-File Report 2015–1048, 96 p.
    Himmelstoss, Emily A., Henderson, Rachel E., Kratzmann, Meridith G., and Farris, Amy S., 2018, Digital Shoreline Analysis System (DSAS) version 5.0 user guide.

    Online Links:

    Other_Citation_Details:
    Himmelstoss, E.A., Henderson, R.E., Kratzmann, M.G., and Farris, A.S., 2018, Digital Shoreline Analysis System (DSAS) version 5.0 user guide: U.S. Geological Survey Open-File Report 2018–1179.
    Gibbs, Ann E., Nolan, Matt, Richmond, Bruce M., Snyder, Alexander G., and Erikson, Li H., 2019, Assessing patterns of annual change to permafrost bluffs along the North Slope coast of Alaska using high-resolution imagery and elevation models.

    Online Links:

    Other_Citation_Details:
    Gibbs, A.E., Nolan, M., Richmond, B.M., Snyder, A.G., Erikson, L.H., 2019, Assessing patterns of annual change to permafrost bluffs along the North Slope coast of Alaska using high-resolution imagery and elevation models: Geomorphology, v. 336, p. 152-164.

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

  1. How well have the observations been checked?
    The attributes in this table record positional and measurement uncertainties calculated during the process of delineating features from the imagery data as described in the process steps. The field names are based on the requirements for use within the Digital Shoreline Analysis System (DSAS) software (Himmelstoss and others, 2018).
  2. How accurate are the geographic locations?
    Data have been delineated from aerial and satellite imagery acquired between 1950 and 2020, the horizontal accuracy of which varies with respect to the data source and the time period. Horizontal accuracy is represented by the UNCY attribute in the file, calculated following the methodology described in Gibbs and Richmond 2015.
  3. How accurate are the heights or depths?
    A formal accuracy assessment of the vertical positional information in the dataset is not applicable.
  4. Where are the gaps in the data? What is missing?
    This file is complete and contains all segments used to calculate change rates where data were available. These data adequately represented the feature position at the time of the imagery.
  5. How consistent are the relationships among the observations, including topology?
    Adjacent bluff edge segments do not overlap. Bluff edges were quality checked for accuracy. Any slight offsets between adjacent segments due to georeferencing and digitizing error are taken into account in the uncertainty calculations.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None
Use_Constraints:
USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - ScienceBase
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? These data are available in shapefile format contained in a single zip file, which also includes CSDGM FGDC-compliant metadata.
  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?
  5. What hardware or software do I need in order to use the data set?
    This zip file contains data available in Environmental Systems Research Institute (Esri) polyline 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 www.esri.com.

Who wrote the metadata?

Dates:
Last modified: 04-Dec-2020
Metadata author:
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Attn: PCMSC Science Data Coordinator
2885 Mission Street
Santa Cruz, CA

831-427-4747 (voice)
pcmsc_data@usgs.gov
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/DataReleases/ScienceBase/DR_P9CRBC5I/BarterIsland_BluffEdge_1950to2020_metadata.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:17:23 2021