Gibbs, Ann E. Ohman, Karin A. Coppersmith, Ryan Richmond, Bruce M. 20240911 vector digital data (polyline) data release 10.5066/F72Z13N1 Pacific Coastal and Marine Science Center, Santa Cruz, CA U.S. Geological Survey https://doi.org/10.5066/F72Z13N1 https://www.sciencebase.gov/catalog/item/663a59b9d34e77890839b077 Gibbs, Ann E. Ohman, Karin A. Coppersmith, Ryan Richmond, Bruce M. 2017 2.0 data release 10.5066/F72Z13N1 Pacific Coastal and Marine Science Center, Santa Cruz, CA U.S. Geological Survey Suggested Citation: Gibbs, A.E., Ohman, K.A., Coppersmith, R., and Richmond, B.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 (ver. 2.0, September 2024): U.S. Geological Survey data release, https://doi.org/10.5066/F72Z13N1. https://doi.org/10.5066/F72Z13N1 This dataset includes a reference baseline used by the Digital Shoreline Analysis System (DSAS) to calculate rate-of-change statistics for the mainland coast of Alaska sheltered by barrier islands from the U.S. Canadian Border to the Hulahula River for the time period 1947 to 2017. 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. Coastal erosion is a persistent process along most open-ocean shores of the United States and affects both developed and natural coastlines. Along the Arctic coast of Alaska, coastal erosion is widespread and threatens communities, defense and energy-related infrastructure, and coastal habitat. As the coast changes, there are a wide range of ways that change can affect coastal communities, habitats, and the physical characteristics of the coast-including beach erosion, shoreline retreat, land loss, and damage to infrastructure. The U.S. Geological Survey (USGS) is responsible for conducting research on coastal change hazards, understanding the processes that cause coastal change, and developing models to forecast future change. To understand and adapt to shoreline change, accurate information regarding the past and present configurations of the shoreline is essential and a comprehensive, nationally consistent analysis of shoreline movement is needed. To meet this national need, the USGS is conducting an analysis of historical shoreline changes along open-ocean coasts of the United States and parts of the Great Lakes. In Alaska, coastlines sheltered from open-ocean wave conditions by barrier islands are also included in the analysis because of their importance to defense and energy-related infrastructure and to understand the similarities, differences, and linkages in coastal behavior and physical processes acting on exposed and sheltered permafrost coastlines. This dataset is one in a series of regionally focused reports on historical shoreline change. As more data are gathered, periodic updates are made, which provide information that can be used in multidisciplinary assessments of global change impacts. 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. 2024 publication date Complete None planned -143.982395 -141.207200 70.136969 69.629756 ISO 19115 Topic Category oceans environment geoscientificInformation Data Categories for Marine Planning Distributions Physical/Chemical Features USGS Thesaurus coastal processes geospatial datasets Marine Realms Information Bank (MRIB) keywords shoreline accretion shoreline erosion None U.S. Geological Survey USGS Coastal and Marine Hazards and Resources Program CMHRP Pacific Coastal and Marine Science Center PCMSC Shoreline Shoreline change Digital Shoreline Analysis System DSAS USGS Metadata Identifier USGS:663a59b9d34e77890839b077 Geographic Names Information System (GNIS) State of Alaska North Slope Beaufort Sea Demarcation Bay Jago River Barter Island Kaktovik Okpilak River Hulahula River None Arctic National Wildlife Refuge United States of America Arctic ANWR No access 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. U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

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Santa Cruz CA 95060 831-427-4747 pcmsc_data@usgs.gov U.S. Geological Survey Generated as a feature class contained in a Personal Geodatabase by DSAS in ArcGIS. Gibbs, A.E. Richmond B.M. 2017 Gibbs, A.E., and Richmond, B.M., 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: U.S. Geological Survey Open-File Report 2017�1107, 21 p. https://doi.org/10.3133/ofr20171107 Ann E. Gibbs Bruce M. Richmond 2015 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. https://doi.org/10.3133/ofr20151048 Emily A. Himmelstoss Rachel E. Henderson Meredith G. Kratzmann Amy S. Farris 2021 Himmelstoss, E.A., Henderson, R.E., Kratzmann, M.G., and Farris, A.S., 2021, Digital Shoreline Analysis System (version 5.1) User Guide: U.S. Geological Survey Open-File Report 2021-1091. https://doi.org/10.3133/ofr20211091 https://pubs.er.usgs.gov/publication/ofr20211091 https://www.usgs.gov/centers/whcmsc/science/digital-shoreline-analysis-system-dsas Emily A. Himmelstoss Amy S. Farris Rachel E. Henderson Meredith G. Kratzmann Ayhan Ergul Ouya Zhang Jessica L. Zichichi E. Robert Thieler 2018 Current software at time of use was 5.1. The second link directs to the DSAS project page. https://code.usgs.gov/cch/dsas/-/tree/v5.1?ref_type=tags https://www.usgs.gov/centers/whcmsc/science/digital-shoreline-analysis-system-dsas The attribute in this layer is based on the requirements for use within the Digital Shoreline Analysis System (DSAS) software (Himmelstoss and others, 2018). The data have been quality checked. 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. 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. 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. 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. Baselines were constructed midshore from the time series of shoreline positions using standard editing tools in Esri ArcMap v. 10.8.1. 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. 5.1 from the baseline, would intersect perpendicular to the general trend of the shorelines. 2024 The baseline feature class was exported from a personal geodatabase to a shapefile in ArcMap v10.8.1 by performing a right-mouse click on the data layer > export > to shapefile (single). 2024 The data were projected in Esri's ArcToolbox v. 10.8.1 > Data Management Tools > Projections and Transformations > Feature > Project. Parameters: input projection = (NAD_1983_2011_Alaska_Albers); output projection = geographic coordinates (WGS84); transformation = WGS_1984_(ITRF08)_To_NAD_1983. The final shoreline dataset was coded with attribute fields Date_, Year_, Uncy, Default_D, DSAS_Include, Source, Source_a, and Shape_Leng. 2024 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). 20260326 Manda Au U.S. Geological Survey Data Management Specialist Mailing

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Santa Cruz CA 95060 831-460-7575 mau@usgs.gov Vector String 23 0.0000001 0.0000001 Decimal degrees WGS_1984 WGS 84 6378137.0 298.257224 Attribute Table Table containing attribute information associated with the data set. U.S. Geological Survey FID Index number unique to each record in the attribute table. Esri Sequential unique whole numbers that are automatically generated. Shape Feature geometry Esri Coordinates defining the feature. 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. U.S. Geological Survey 28 50 Group This is an optional field used by the Digital Shoreline Analysis System (DSAS) software for data management purposes. The summary report text file that is generated each time rate calculations are run uses the group attribute field to provide rate averages for each group. Here the groups represent coastal sub-region ID as defined in Gibbs and Richmond (2017). Himmelstoss and others (2021) and Gibbs and Richmond (2017) 1 U.S. Canadian border to the Hulahula River U.S. Geological Survey 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. 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. U.S. Geological Survey - ScienceBase Mailing and Physical

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Denver CO 80225 1-888-275-8747 sciencebase@usgs.gov These data are available in shapefile format contained in a single zip file, which also includes CSDGM FGDC-compliant metadata. 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. Vector Digital Data Set (Polyline) ArcGIS Desktop 10.8.1 Esri polyline shapefile These files (.cpg, .dbf, .prj, .sbn, .sbx, .shp, and .shx) are a collection of files with a common filename prefix and must be downloaded and stored in the same directory. Together they are the components of the shapefile and include FGDC CSDGM-compliant metadata. Use WinZip or equivalent 0.028 https://www.sciencebase.gov/catalog/file/get/663a59b9d34e77890839b077 https://www.sciencebase.gov/catalog/item/663a59b9d34e77890839b077 https://doi.org/10.5066/F72Z13N1 Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to download the zipped file of data and metadata. The second link points to a landing page with metadata and data. The third link points to the landing page for the overall data release. None These data are available in a polyline shapefile format. The user must have software to read and process the data components of a shapefile. 20260326 U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

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Santa Cruz CA 95060 831-427-4747 pcmsc_data@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998