Shorelines from 1948 to 2016 for the north coast of Alaska, Icy Cape to Cape Prince Wales used in shoreline change analysis

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?
   Snyder, Alexander G., and Gibbs, Ann E., 20191227, Shorelines from 1948 to 2016 for the north coast of Alaska, Icy Cape to Cape Prince Wales used in shoreline change analysis: data release DOI: 10.5066/P9H1S1PV, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

   Online Links:

   • https://doi.org/10.5066/P9H1S1PV
   • https://www.sciencebase.gov/catalog/item/5dbb7ac3e4b06957974eda38

   This is part of the following larger work.
   Snyder, Alexander G., and Gibbs, Ann E., 2019, National Assessment of Shoreline Change: A GIS compilation of vector shorelines and associated shoreline change data for the north coast of Alaska, Icy Cape to Cape Prince of Wales: data release DOI:10.5066/P9H1S1PV, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

   Online Links:

   • https://doi.org/10.5066/P9H1S1PV

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -168.125477210333
   East_Bounding_Coordinate: -161.551585613264
   North_Bounding_Coordinate: 70.3304809057524
   South_Bounding_Coordinate: 65.6000415003095
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 01-Jul-1948

   Ending_Date: 03-Sep-2016

   Currentness_Reference:

   Ground condition

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

   Geospatial_Data_Presentation_Form: polyline shapefile
   

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 (3168)
   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 0.0196106556. Longitudes are given to the nearest 0.0558147069. 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 dataset. (Source: Producer defined)

   FID

   Index number unique to each record in the attribute table. (Source: Assigned by ArcMap.)

   Range of values
   Minimum:	0
   Maximum:	2327

   Shape

   Defines what type of spatial information is associated with this record (for example, polyline, polygon, point). (Source: Assigned by ArcMap.)

   Value	Definition
   Polyline	A shape defined by one or more paths, in which a path is a series of connected segments.

   DATE_

   Date on which the source imagery for the digitized shorelines was collected. The precision of the date provided is specified in the ‘Default_D’ field. When only the year was defined, July 1 was used for the month and day. When only the month and year were defined, the first of the month was used. (Source: Producer defined.)

   Range of values
   Minimum:	07/01/1948
   Maximum:	09/03/2016
   Units:	Days, Months, Years

   Year_

   Year in which the source imagery for the digitized shorelines was collected. (Source: Producer defined.)

   Range of values
   Minimum:	1948
   Maximum:	2016
   Units:	Years
   Resolution:	1

   Uncy

   total shoreline position uncertainty, in meters. Actual shoreline position is within the range of this value. The uncertainty was determined by equation 1 in Gibbs and others (2019). (Source: Producer defined.)

   Range of values
   Minimum:	1
   Maximum:	22.4
   Units:	Meters
   Resolution:	0.1

   Default_D

   Number that indicates the precision of the source imagery collection date. (Source: Producer defined.)

   Value	Definition
   0	The year, month, and day of source imagery collection are known.
   1	The year of source imagery collection is known.
   2	The year and month of source imagery collection are known.

   Source

   Identifies the source of the map or imagery from which the shorelines in this dataset were digitized. (Source: Producer defined.)

   Value	Definition
   NOAA, T-Sheet	National Oceanographic and Atmospheric Administration Topographic Sheets.
   NASA, Alaska High Altitude Photography	Orthorectified Alaska high altitude photography mosaics
   Fairbanks FODAR SfM – State of Alaska Orthoimagery	Orthorectified aerial photo mosaics generated by Fairbanks FODAR using Structure from Motion (SfM).
   Lestak and others, 2010	Published shorelines generated by Lestak and others (2010) using orthorectified photo mosaics.

   Source_a

   Identification numbers used by the organization that produced the imagery or map from which the shorelines were digitized. The identification number convention varies base on the source of the map or imagery, which is identified in the attribute 'Source'. NOAA, T-sheets: refers to the unique identification number on the original topographic maps. NASA--Alaska High Altitude Photography: refers to the unique identification number given to individual image files produced by the organization that post-processed the imagery. Lestak and others 2010: refers to the unique identification number given to individual image files produced by the organization that post-processed the imagery. Fairbanks FODAR SfM--USGS Orthoimagery: refers to the unique identification number given to individual image files produced by the organization that post-processed the imagery. (Source: Producer defined.) Unique identifier assigned by the organization that produced the source data

   Shape_Leng

   Length of the shoreline segment. (Source: Producer defined)

   Range of values
   Minimum:	10.298835
   Maximum:	21098.001620
   Units:	Meters

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Alexander G. Snyder
   • 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?

Beach erosion is a persistent problem along most open-ocean shores of the United States. Along the Arctic coast of Alaska, coastal erosion is widespread and is threatens Native communities, defense and energy-related infrastructure, and coastal habitat. As coastal populations continue to expand and infrastructure and habitat are increasingly threatened by erosion, there is increased demand for accurate information regarding past and present trends and rates of shoreline movement. There also is a need for a comprehensive analysis of shoreline change with metrics that are consistent from one coastal region to another. To meet these national needs, the U.S. Geological Survey is conducting an analysis of historical shoreline changes along the open-ocean sandy shores of the conterminous United States and parts of Hawaii, Alaska, and the Great Lakes. One purpose of this work is to develop standard, repeatable methods for mapping and analyzing shoreline change so that periodic, systematic, and internally consistent updates regarding coastal erosion and land loss can be made nationally.

How was the data set created?

1. From what previous works were the data drawn?

   T-sheets (source 1 of 5)

   National Oceanic and Atmospheric Administration, Unpublished material, Topographic sheets (T-sheets): National Oceanic and Atmospheric Administration, online.

   Online Links:

   • https://nosimagery.noaa.gov/images/shoreline_surveys/survey_scans/NOAA_Shoreline_Survey_Scans.html

   Type_of_Source_Media: Digital Data (.tif)
   Source_Contribution: T-sheet imagery was used to delineate the MHW shoreline.
   

   AHAP (source 2 of 5)

   U.S. Fish and Wildlife Service, Arctic Landscape Conservation Cooperative, and University of Alaska, Fairbanks’ Alaska Satellite Facility and the Geographic Information Network of Alaska, 2012, Orthorectified 1:64,000-scale color-infrared Alaska High-Altitude Aerial Photography: Unpublished data, Unpublished data.

   Type_of_Source_Media: Digital Data (.tif)
   Source_Contribution:

   Alaska high altitude aerial photography was used to delineate the instantaneous land-water interface shoreline.

   AHAP (source 3 of 5)

   U.S. Geological Survey, and Far North Geospatial, LLC, Unpublished material, Orthorectified 1:64,000-scale color-infrared Alaska High-Altitude Aerial Photography: Unpublished data, Unpublished data.

   Type_of_Source_Media: Digital Data (.tif)
   Source_Contribution:

   Alaska high altitude aerial photography was used to delineate the instantaneous land-water interface shoreline.

   Fodar (source 4 of 5)

   Overbeck, J. R., Hendricks, M. D., and N. E. M. Kinsman, 2017, Photogrammetric digital surface models and orthoimagery for the continuous coastline, Wales to Platinum, Alaska, segment A: Wales to Teller.: Alaska Division of Geological & Geophysical Surveys, online.

   Online Links:

   • http://dggs.alaska.gov/pubs/id/29771

   Type_of_Source_Media: Digital Data (.tif)
   Source_Contribution:

   Fodar imagery was used to delineate the instantaneous land-water interface shoreline.

   Fodar (source 5 of 5)

   U.S. Geological Survey, and Fodar, Fairbanks, Unpublished material, Orthorectified natural color aerial photography for the continuous coastline, Icy Cape to Cape Prince of Wales: Unpublished data, Unpublished data.

   Type_of_Source_Media: Digital Data (.tif)
   Source_Contribution:

   Fodar imagery was used to delineate the instantaneous land-water interface shoreline.

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

   Date: 2019 (process 1 of 5)

   High-resolution scans of T-sheets were geo-registered using Esri ArcMap software (v10.6) by placing 4 well-spaced registration points at gridline intersections of registered T-Sheets of lower resolution and applying a first-order polynomial transformation. An additional 1-10 ground control points (GCPs) were placed using benchmarks and geomorphic features with known locations, then applying a first-order polynomial transformation.

   Date: 2019 (process 2 of 5)

   Vector shorelines were digitized from all data sources using standard editing tools in ArcMap 10.6 using criteria described in Gibbs and others (2019).

   Date: 2019 (process 3 of 5)

   Attributes describing geomorphic setting and specifics of source data were added to vector shorelines.

   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: 13-Oct-2021 (process 5 of 5)

   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

3. What similar or related data should the user be aware of?
   Gibbs, Ann E., Snyder, Alexander G., and Richmond, Bruce M., 2019, National Assessment of Shoreline Change: Historical Shoreline Change Along the North Coast of Alaska, Icy Cape to Cape Prince of Wales..

   Online Links:

   • https:/doi.org/10.3133/ofr20191146

   Other_Citation_Details:

   Gibbs, A.E., Snyder, A.G., Richmond, B.M., 2019, National Assessment of Shoreline Change: Historical Shoreline Change Along the North Coast of Alaska, Icy Cape to Cape Prince of Wales: U.S. Geological Survey Open-File Report 2019-1146.

   Thieler, Robert E., Himmelstoss, Emily A., Zichichi, Jessica L., and Ergul, Ayhan, 2009, Digital Shoreline Analysis System (DSAS) version 4.0 - An ArcGIS extension for calculating shoreline change.

   Online Links:

   • https://doi.org/10.3133/ofr20081278

   Other_Citation_Details:

   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: U.S. Geological Survey Open-File Report 2008-1278.

   Lestak, L. R., Manley, W. F., and Parrish, E. G., 2010, Digital Shoreline Analysis of Coastal Change in Bering Land Bridge NP (BELA) and Cape Krusenstern NM (CAKR).

   Other_Citation_Details:

   Lestak, L.R., Manley, W.F., and Parrish, E.G., 2010, Digital Shoreline Analysis of Coastal Change in Bering Land Bridge NP (BELA) and Cape Krusenstern NM (CAKR), Northwest Alaska: Fairbanks, AK: National Park Service, Arctic Network I&M Program. Digital Media.

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 and datum offsets calculated during the process of extracting a land/water interface shoreline from the orthoimagery 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 (USGS Open-File Report 2008-1278).
2. How accurate are the geographic locations?
   Shoreline data have been acquired from 1948 to 2016, the horizontal accuracy of which varies with respect to the data source from which the shorelines were digitized and the time period. Shorelines digitized from the 1980s era Alaska High Altitude Photography (AHAP) have an estimated shoreline position uncertainty of plus or minus 10.4 to 22.4 meters. Shorelines digitized from the 1940s and 1950s era T-sheets have an estimated total shoreline position uncertainty of plus or minus 15.7 meters. Shorelines digitized from 2016 orthophotographs have an estimated total shoreline position uncertainty of plus or minus 2.1 to 3.8 meters. Shorelines used in this analysis that were published in Lestak and others (2010) have an estimated total shoreline position uncertainty ranging from 2.3 to 2.9 meters, 2.2 to 2.7 meters, and 1.7 to 1.0 meters for orthoimagery collected in the 1950s, 1980s, and 2003, respectively. Please visit the 'Estimation of Shoreline Position Uncertainty' section in Gibbs and others (2019) 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 dataset 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 specified Alaska coastal region where shoreline position data were available. These data adequately represented the shoreline position at the time of the survey. Remaining gaps in these data are a consequence of nonexisting 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 Gibbs and others (2019).

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?
   • Availability in digital form:

     Data format:	Zip file contains digitized shoreline position representing the land/water interface on the northern coast of Alaska. in format Shapefile (version ArcGIS Desktop 10.6) Esri polyline shapefile Size: 3.2
     Network links:	https://www.sciencebase.gov/catalog/file/get/5dbb7ac3e4b06957974eda38?facet=WestChukchi_shorelines https://doi.org/10.5066/P9H1S1PV

   • 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: 13-Oct-2021

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:

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