Shorelines for the northern Alaska coastal region used in shoreline change analysis, 1947 to 2012

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Frequently anticipated questions:

What does this data set describe?

Title:
Shorelines for the northern Alaska coastal region used in shoreline change analysis, 1947 to 2012
Abstract:
The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and encompasses unique habitats of global significance. Coastal erosion along the north coast of Alaska is chronic, widespread, may be accelerating, and is threatening defense and energy-related infrastructure, natural shoreline habitats, and Native communities. There is an increased demand for accurate information regarding past and present shoreline changes across the United States. To meet these national needs, the Coastal and Marine Geology Program of the U.S. Geological Survey (USGS) is compiling existing reliable historical shoreline data along sandy shores of the conterminous United States and parts of Alaska and Hawaii under the National Assessment of Shoreline Change project. There is no widely accepted standard for analyzing shoreline change. Existing shoreline data measurements and rate calculation methods vary from study to study and prevent combining results into state-wide or regional assessments. The impetus behind the National Assessment project was to develop a standardized method of measuring changes in shoreline position that is consistent from coast to coast. The goal was to facilitate the process of periodically and systematically updating the results in an internally consistent manner.
  1. How might this data set be cited?
    U.S. Geological Survey, 2015, Shorelines for the northern Alaska coastal region used in shoreline change analysis, 1947 to 2012: Open-File Report 2015-1030, U.S. Geological Survey, Coastal and Marine Geology Program, Pacific Coastal and Marine Science Center, Santa Cruz and Menlo Park, CA.

    Online Links:

    This is part of the following larger work.

    Gibbs, Ann E., 2015, National Assessment of Shoreline Change: A GIS Compilation of Vector Shorelines and Associated Shoreline Change Data for the North Coast of Alaska, U.S.-Canadian Border to Icy Cape: Open-File Report 2015-1030, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -161.954353051
    East_Bounding_Coordinate: -156.475510823
    North_Bounding_Coordinate: 71.389682113
    South_Bounding_Coordinate: 70.2327821789
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 1947
    Ending_Date: 2012
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: 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):
      • String (164)
    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 0.0196083139. Longitudes are given to the nearest 0.0572155717. Latitude and longitude values are specified in Decimal seconds. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
  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 of shoreline position; date of survey as indicated on source material. A default date of 07/01 was assigned to shorelines where only the year was known (month and day unknown). Using July, the mid-point month of the calendar year, minimizes the potential offset to the actual shoreline date by a maximum of six months. (Source: U.S. Geological Survey)
    ValueDefinition
    06/21/2010Unknown
    07/01/1949Unknown
    07/24/2010Unknown
    07/25/2005Unknown
    08/01/1947Unknown
    08/02/2010Unknown
    08/12/2012Unknown
    09/12/2011Unknown
    Uncy
    Estimate of total estimated shoreline position uncertainty. Actual shoreline position is within the range of this value (plus or minus, meters). The uncertainty was determined by the equation in USGS Open-File Report (OFR) 2015-1030 (cross-referenced in this metadata file). (Source: U.S. Geological Survey)
    Range of values
    Minimum:6
    Maximum:16
    Default_D
    Differentiates between shorelines that have known month and day attributes and those that use the default value of 07/01 when only the year is known. (Source: U.S. Geological Survey)
    ValueDefinition
    0Shoreline month and day are known
    1Shoreline month and day are unknown and default value of 07/01 was used
    Year_
    Four digit year of shoreline (Source: U.S. Geological Survey)
    Range of values
    Minimum:1947
    Maximum:2012
    Source
    Agency that provided shoreline feature and the data source used to digitize shoreline feature. (Source: U.S. Geological Survey)
    ValueDefinition
    Alaska SDMI orthoimageryState of Alaska Digital Mapping Initiative orthoimagery (http://www.alaskamapped.org/ortho/)
    NOAA Nautical ChartNational Oceanographic and Atmospheric Administration Nautical Charts
    NOAA T-SheetNational Oceanographic and Atmospheric Administration Topographic Sheets
    USGS - DOQQsU.S. Geological Survey Digital Orthophoto Quarter Quandragle orthophotgraphy
    USGS - lidarU.S. Geological Survey northern Alaska coastal lidar elevation data
    Source_a
    Specific source ID of data used used to digitize shoreline feature. (Source: U.S. Geological Survey) Unknown
    Shape_Leng
    Length of feature in meters units (Source: Esri)
    Range of values
    Minimum:107.402945742
    Maximum:69570.3592386
    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 was 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)
    • U.S. Geological Survey
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    U.S. Geological Survey
    Attn: Ann E. Gibbs
    Pacific Coastal and Marine Science Center
    Santa Cruz, CA
    USA

    831-460-7540 (voice)
    831-427-4748 (FAX)
    agibbs@usgs.gov

Why was the data set created?

This dataset includes shorelines from ranging from 1947 to 2012 for the north coast of Alaska between the U.S.-Canadian Border and Icy Cape. Shorelines were compiled from T-sheets (National Oceanic and Atmospheric Administration), aerial orthophotographs (U.S. Geological Survey, ConocoPhillips and BP-Alaska), QuickBird satellite imagery (U.S. Fish and Wildlife Service), and lidar (U.S. Geological Survey). Historical shoreline positions serve as easily understood features that can be used to describe the movement of beaches through time. These data are used to calculate rates of shoreline change for the U.S. Geological Survey's (USGS) National Assessment Project. Rates of shoreline change were generated in a GIS using the Digital Shoreline Analysis System (DSAS) version 4.3. DSAS uses a measurement baseline method to calculate rate-of-change statistics. Transects are cast from the reference baseline to intersect each shoreline, establishing measurement points used to calculate shoreline change rates.

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: 2009 (process 1 of 11)
    Shoreline data were sought in an effort to compile as many quality shorelines as possible for the region. T-sheets were obtained from NOAA as scanned raster images. Aerial photos were acquired from USGS Alaska Science Center, ConocoPhillips, and BP-Alaska. QuickBird satellite imagery was acquired from U.S. Fish and Wildlife Service. Lidar data were acquired from USGS.
    Date: 2009 (process 2 of 11)
    T-sheets were geo-registered using Esri ArcMap software (v.9.3) by placing 8-20 well-spaced ground control points (GCP) at gridline intersections and applying a third order polynomial transformation. Some T-sheets may have required additional coordinate transformation information from NOAA to account for datum offsets between historical datums (USSD) and modern datums (NAD27 or NAD83). Datum transformations were applied to GCP coordinates prior to registration. Total RMS error for the rectification process was maintained below 0.0001 degrees, which is approximately 11 m at this latitude. Typically the resulting RMSE was much lower than 0.0001 degree.
    Date: 2010 (process 3 of 11)
    Vector shorelines were digitized from all data sources using standard editing tools in ArcMap v9.3. Quality assessments were performed and shorelines were edited to remove any overlap between adjacent shorelines.
    Date: 2010 (process 4 of 11)
    T-sheet derived shorelines were projected in Esri's ArcToolbox (v.9.3) Data Management Tools >; Projections and Transformations >; Feature >; Project. Parameters: input projection = geographic (NAD 83); output projection = UTM zone XN (NAD 83; where X is the corresponding UTM zone).
    Date: 2011 (process 5 of 11)
    Shorelines from all sources were merged in Esri?s ArcToolbox; Data Management Tools > General > Merge to produce a single shoreline file for each UTM zone. The final shoreline dataset was coded with attribute fields Date_, Uncy, Default_D, Year_, Source, Source_a, and Shape_Leng.
    Date: 2012 (process 6 of 11)
    The appended shoreline file was imported into a personal geodatabase in ArcCatalog v9.3 by right-clicking on the geodatabase > Import (feature class) for use with the Digital Shoreline Analysis System (DSAS) v4.3 software to perform rate calculations.
    Date: 2014 (process 7 of 11)
    The shoreline feature class was exported from the personal geodatabase back to a shapefile in Esri?s ArcCatalog v10.1 by right-clicking on the shoreline file > Export > To Shapefile (single) for publication purposes.
    Date: 2014 (process 8 of 11)
    The data were projected in Esri?s ArcToolbox v10.1 > Data Management Tools > Projections and Transformations > Feature > Project. Parameters: input projection = UTM zone XN (NAD83; where X is the corresponding UTM zone); output projection = geographic coordinates (WGS84); transformation = WGS_1984_(ITRF00)_To_NAD_1983.
    Date: 07-Feb-2017 (process 9 of 11)
    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 10 of 11)
    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 11 of 11)
    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
  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: Open-File Report 2015-1030, U.S. Geological Survey, Coastal and Marine Geology Program, Santa Cruz, CA.

    Online Links:

    Thieler, E.R., Himmelstoss, E.A., Zichichi, J.L., and Ergul, A., 2009, Digital Shoreline Analysis System (DSAS) version 4.0 - An ArcGIS extension for calculating shoreline change: Open-File Report 2008-1278, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole, MA.

    Online Links:

    Other_Citation_Details: Current version at time of use was 4.3
    National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Unknown, Scanned National Ocean Service (NOS) Coastal Survey Maps (also known as Topographic Survey sheets, or T-sheets): NOAA shoreline manuscripts (T-sheets) unknown, National Oceanic and Atmospheric Administration, Washington, D.C..

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

  1. How well have the observations been checked?
    The data provided here are a compilation of shorelines from multiple sources, spanning 65 years. The attributes are based on the requirements of the Digital Shoreline Analysis System (DSAS) software and have gone through a series of quality assurance procedures.
  2. How accurate are the geographic locations?
    Shoreline data have been acquired from 1947 to 2012, the horizontal accuracy of which varies with respect to data source from which the shorelines were digitized and the time period. Shorelines digitized from the 1940s T-sheets have an estimated total shoreline position uncertainty of plus or minus 16 meters. Shorelines generated from 1997-2007 orthophotos have an estimated total shoreline position uncertainty of plus or minus 3-4 meters. Shorelines generated from 2003 QuickBird imagery, 2002 and 2005 USGS Digital Orthophoto Quarter-Quadrangles(DOQQs), and 2010-2012 lidar data have an estimated total shoreline position uncertainty of plus or minus 6 meters. Please visit the ?Shoreline Position Uncertainty' section in the corresponding USGS Open-File Report (Gibbs and others, 2014; http://pubs.usgs.gov/of/2015/1030/)for a complete explanation of the measurement uncertainties associated with these shorelines.
  3. How accurate are the heights or depths?
    A formal accuracy assessment of the vertical positional information in the data set has either not been conducted, or is not applicable.
  4. Where are the gaps in the data? What is missing?
    This shoreline file is complete and contains all shoreline segments used to calculate shoreline change rates along sections of the north coast of Alaska, between the U.S.-Canadian border and Icy Cape, where shoreline position data were available. These data adequately represented the shoreline position at the time of the survey. Remaining gaps in these data, if applicable, are a consequence of non-existing data or existing data that did not meet quality assurance standards.
  5. How consistent are the relationships among the observations, including topology?
    Adjacent shoreline segments do not overlap and are not necessarily continuous. Shorelines 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 included in the corresponding report.

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:
This information is not intended for navigational purposes. Read and fully comprehend the metadata prior to data use. Uses of these data should not violate the spatial resolution of the data. Where these data are used in combination with other data of different resolution, the resolution of the combined output will be limited by the lowest resolution of all the data. Acknowledge the U.S. Geological Survey in products derived from these data. Share data products developed using these data with the U.S. Geological Survey. This database has been approved for release and publication by the Director of the USGS. Although this database has been subjected to rigorous review and is 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 this Federal Geographic Data Committee-compliant metadata file is intended to document these data in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey
    Pacific Coastal and Marine Science Center
    Santa Cruz, CA
    USA

    831-460-7540 (voice)
    831-427-4748 (FAX)
  2. What's the catalog number I need to order this data set? EastChukchi_shorelines.zip
  3. What legal disclaimers am I supposed to read?
    This information is not intended for navigational purposes. This database has been approved for release and publication by the Director of the USGS. Although this database has been subjected to rigorous review and is 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. 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.
  4. How can I download or order the data?
    • Availability in digital form:
      Data format: This WinZip file contains a shapefile of historic shorelines from 1947 to 2012 for the shorelines of the Alaska North Coast region from the U.S.-Canadian border to Icy Cape and associated metadata. in format vector digital data (version 9.0) Esri polyline shapefile Size: 0.418
      Network links: http://pubs.usgs.gov/of/2015/1030/downloads/EastChukchi_shorelines.zip
    • Cost to order the data: None

  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: 19-Oct-2020
Metadata author:
Ann E. Gibbs
U.S. Geological Survey
Geologist
Pacific Coastal and Marine Science Center
Santa Cruz, CA
USA

831-460-7540 (voice)
831-427-4748 (FAX)
agibbs@usgs.gov
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/SeriesReports/OFR/OFR_2015-1030/EastChukchi_shorelines.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:17:53 2021