Alaska: East Chukchi Sea Coast (Point Barrow to Icy Cape) offshore baselines for the exposed coast generated to calculate shoreline change rates

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Frequently anticipated questions:

What does this data set describe?

Title:
Alaska: East Chukchi Sea Coast (Point Barrow to Icy Cape) offshore baselines for the exposed coast generated to calculate shoreline change rates
Abstract:
This dataset includes a reference baseline used by the Digital Shoreline Analysis System (DSAS) to calculate rate-of-change statistics for the exposed north coast of Alaska coastal region between Point Barrow and Icy Cape for the time period 1947 to 2012. This baseline layer serves as the starting point for all transects cast by the DSAS application and can be used to establish measurement points used to calculate shoreline-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 data set 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., Ohman, Karin A., Coppersmith, Ryan, and Richmond, Bruce M., 2017, Alaska: East Chukchi Sea Coast (Point Barrow to Icy Cape) offshore baselines for the exposed coast generated to calculate shoreline change rates: data release 10.5066/F72Z13N1, U.S. Geological Survey, U.S. Geological Survey, 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., Ohman, Karin A., Coppersmith, Ryan, and Richmond, Bruce M., 2017, National Assessment of Shoreline Change: A GIS compilation of Updated Vector Shorelines and Associated Shoreline Change Data for the North Coast of Alaska, U.S. Canadian Border to Icy Cape: data release 10.5066/F72Z13N1, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -161.956935191
    East_Bounding_Coordinate: -156.478282888
    North_Bounding_Coordinate: 71.3906930822
    South_Bounding_Coordinate: 70.2876270518
    Description_of_Geographic_Extent:
    North coast of Alaska between the Colville River Delta and Point Barrow
  3. What does it look like?
    EastChukchiExtent.jpg (JPEG)
    Map of the East Chukchi subregion of the north coast of Alaska shoreline change assessment area.
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2017
    Currentness_Reference:
    publication date
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: vector digital data (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 (9)
    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 0.0196081946. Longitudes are given to the nearest 0.0572891920. 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)
    ID
    Field required by the Digital Shoreline Analysis System (DSAS) software. DSAS uses this value to determine the ordering sequence of transects when the baseline feature contains multiple segments. Individual segments are numbered sequentially alongshore. (Source: U.S. Geological Survey)
    Range of values
    Minimum:1
    Maximum:9
    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)
    • Gibbs, Ann E.
    • Ohman, Karin A.
    • Coppersmith, Ryan
    • Richmond, Bruce M.
  2. Who also contributed to the data set?
    U.S. Geological Survey
  3. To whom should users address questions about the data?
    Ann E. Gibbs
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    2885 Mission Street
    Santa Cruz, CA
    USA

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

Why was the data set created?

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 Alaskan 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.

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: 2016 (process 1 of 5)
    Baselines were constructed offshore from the time series of shoreline positions using standard editing tools in Esri ArcMap v. 10.3 The baselines were positioned to conform to changes in the orientation of the historical shorelines also presented in this data release. This was done so that transects, which are generated by the Digital Shoreline Analysis System v 4.3 from the baseline, would intersect perpendicular to the general trend of the shorelines.
    Date: 2016 (process 2 of 5)
    The baseline feature class was exported from a personal geodatabase to a shapefile in ArcCatalog (v.10.3) by performing a right-mouse click on the data layer > export > to shapefile (single).
    Date: 2016 (process 3 of 5)
    The baseline shapefile was projected in Esri's ArcToolbox (v.10.3) > 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 (WGS 84) using the Geographic Transformation WGS_1984_(ITRF00)_To_NAD_1983.
    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: 26-Mar-2026 (process 5 of 5)
    The metadata title was modified to move the location to the beginning of the title. This was done to meet new system requirements as ScienceBase is migrated to a new platform, and to keep datasets grouped by location on the new data release landing page. (20260326). Person who carried out this activity:
    Manda Au
    U.S. Geological Survey
    Data Management Specialist
    2885 Mission Street
    Santa Cruz, CA

    831-460-7575 (voice)
    mau@usgs.gov
  3. What similar or related data should the user be aware of?
    Gibbs, A.E., and B.M., Richmond, 2017, National Assessment of Shoreline Change: Summary Statistics for Updated Vector Shorelines and Associated Shoreline Change Data for the North Coast of Alaska, U.S.--Canadian Border to Icy Cape: Open-File Report 2017-1107, U.S. Geological Survey, Reston, VA.

    Online Links:

    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 2015-1048, U.S. Geological Survey, Reston, VA.

    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, Reston, VA.

    Online Links:

    Other_Citation_Details: Current version at time of use was 4.3

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

  1. How well have the observations been checked?
    The attribute in this layer is based on the requirements for use within the Digital Shoreline Analysis System (DSAS) software (Theiler and others, 2009). The data have been quality checked.
  2. How accurate are the geographic locations?
    The baseline serves as a reference point for transects cast by the Digital Shoreline Analysis System (DSAS) software. It does not correspond to any real-world feature.
  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 baseline file is complete and contains all baseline segments used to cast transects where shoreline data are present to calculate a rate of change.
  5. How consistent are the relationships among the observations, including topology?
    All polylines have a unique identification attribute (ID). This field is used by the Digital Shoreline Analysis System (DSAS) to designate the alongshore order of baselines if there are more than one. Adjacent baseline segments do not overlap and are not necessarily continuous.

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 - Science Base
    CenterDenver Federal Center, Building 810, Mail Stop 302
    Denver, CO
    CA

    888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? EastChukchi_exposed_baseline.shp
  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: 26-Mar-2026
Metadata author:
Ann E. Gibbs
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Geologist
2885 Mission Street
Santa Cruz, CA
USA

831-460-7540 (voice)
831-427-4748 (FAX)
agibbs@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/DataReleases/ScienceBase/DR_F72Z13N1/EastChukchi_exposed_baseline.faq.html>
Generated by mp version 2.9.51 on Fri Apr 24 15:25:52 2026