Alaska Coastal Profile Tool (ACPT)

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Frequently anticipated questions:

What does this data set describe?

Title: Alaska Coastal Profile Tool (ACPT)
Abstract:
Alaska Coastal Profile Tool (ACPT), Digital Data Series 7 v.2, provides shoreface elevation measurements collected by various stakeholders since the 1960s; many of which are unpublished or inaccessible. Since May 30, 1975, Alaska Division of Geological & Geophysical Surveys (DGGS) staff and others have compiled statewide elevation profiles to preserve historical coastal data, establish a centralized repository for future datasets, and support consistent, accurate, and repeatable observations along existing profiles. These shore-normal measurements are especially valuable when sites are revisited seasonally or interannually, helping to document change and assess vulnerability in Alaska's dynamic coastal environments. The database accommodates diverse data collection methods, including differential leveling, survey-grade global positioning system (GPS), and digital elevation model extraction. It incorporates contributions from community-led efforts and state, federal, and academic partners. For this version 2 release, DGGS integrated previously stored data with post-update acquisitions and reprocessed the data to improve the reliability of comparative analyses and the precision of future datasets. The database will be updated as new data become available, ensuring that derived products evolve. Its open-access design encourages broad participation in community-based coastal monitoring and fosters a deeper understanding of shoreline change across the state. All files can be downloaded from the Alaska Division of Geological & Geophysical Surveys website (http://doi.org/10.14509/31747).
Supplemental_Information: 
alaska coastal profile tool:    The Alaska coastal profile tool is an open‑access repository of shoreline elevation measurements collected across Alaska since the 1960s.
  1. How might this data set be cited?
    Horen, K.C., Nieminski, N.M., and Staff, DGGS, 2025, Alaska Coastal Profile Tool (ACPT): Digital Data Series DDS 7 v.2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 3 p
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -171.790705
    East_Bounding_Coordinate: -138.486856
    North_Bounding_Coordinate: 71.348288
    South_Bounding_Coordinate: 55.276746
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 1960
    Ending_Date: 2025
    Currentness_Reference:
    publication date
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: 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.
    2. What coordinate system is used to represent geographic features?
      The horizontal datum used is WGS84.
      The ellipsoid used is WGS 84.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257223563.
  7. How does the data set describe geographic features?
    alaska coastal profile tool
    The Alaska coastal profile tool is an open‑access repository of shoreline elevation measurements collected across Alaska since the 1960s. (Source: DGGS)

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
  2. Who also contributed to the data set?
    This work was made possible with U.S. Geological Survey, Coastal Marine Hazards Resource Program funding through an Alaska Climate Adaptation Science Center funding opportunity. The views and conclusions contained in this document are those of the author and should not be interpreted to represent the opinions or policies of the Alaska Division of Geological & Geophysical Surveys, the U.S. Geological Survey, or the U.S. Government. Mention of trade names or commercial products does not constitute endorsement by the Alaska Division of Geological & Geophysical Surveys, the U.S. Geological Survey, or the U.S. Government.
  3. To whom should users address questions about the data?
    Alaska Division of Geological & Geophysical Surveys
    GIS Manager
    3354 College Rd
    Fairbanks, AK
    USA

    907-451-5020 (voice)
    dggsgis@alaska.gov
    Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays

Why was the data set created?

The Alaska coastal profile database preserves and centralizes shoreline elevation measurements to document coastal change and assess climate-related vulnerability. Its purpose is to provide Alaska communities with consistent, accurate, and repeatable observations that support monitoring and decision-making in dynamic coastal environments.

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: 2014 (process 1 of 2)
    Geodatabase deployment - DGGS staff, in cooperation with the Alaska Ocean Observing System (AOOS), initiated the Alaska coastal profile database in 2014. The database was a universal repository of coastal elevation profiles compiled from original, published, and unpublished measurements across Alaska's coastal zone. Field data were collected with survey‑grade GPS using differential and real‑time kinematic methods, supplemented by digital elevation model extractions and manually added field information in ArcGIS. All positional information was transformed into the WGS84 datum, visually checked for consistency, and organized for interactive online mapping. Designed to accommodate diverse collection techniques, the database provided an accessible map interface that enabled easy access to existing profiles, promoted partner and community involvement in coastal monitoring, and was periodically updated as new data became available.
    Date: 2025 (process 2 of 2)
    Version update - For the version 2 update, DGGS staff redesigned the Alaska coastal profile database in 2025. The update incorporated data from the existing repository along with new measurements collected since the previous release. DGGS reprocessed the combined datasets to improve accuracy, organized observations by collocation to group measurements across time, and applied statistical methods to define consistent profiles. For each profile, DGGS calculated the centroid, performed principal component analysis to determine the primary axis, and normalized coordinates relative to the centroid. A covariance matrix was constructed, eigendecomposition identified major and minor axes, and the farthest observations were used to establish profile origins and directions. Linear distances were then calculated along the primary axis, producing computed profiles that reconciled past lower‑precision data and provided a framework to enhance the precision of future collections.
  3. What similar or related data should the user be aware of?
    Buzard, R.M., Overbeck, J.R., and Maio, C.V., 2019, Community-based methods for monitoring coastal erosion: Information Circular IC 84, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 35 p
    Buzard, R.M., Overbeck, J.R., Chriest, Jonathan, Endres, K.L., and Plumb, E.W., 2021, Coastal flood impact assessments for Alaska communities: Report of Investigation RI 2021-1, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 16 p
    Buzard, R.M., Turner, M.M., Miller, K.Y., Antrobus, D.C., and Overbeck, J.R., 2021, Erosion exposure assessment of infrastructure in Alaska coastal communities: Report of Investigation RI 2021-3, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 29 p
    Staff, DGGS, 2015, Alaska Shoreline Change Tool: Digital Data Series DDS 9, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Gould, A.I., Kinsman, N.E.M., and Hendricks, M.D., 2015, Guide to projected shoreline positions in the Alaska shoreline change tool: Miscellaneous Publication MP 158, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 11 p
    Horen, K.C., Poisson, A.C., Christian, J.E., and Nieminski, N.M., 2024, Methods for evaluating coastal flood impacts in Alaska communities: Miscellaneous Publication MP 177, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 13 p
    Overbeck, J.R., 2017, Storm water level feature extraction from digital elevation models using intra-storm photographs: Report of Investigation RI 2017-6, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 10 p
    Overbeck, J.R., 2018, Coastal flooding & erosion in Alaska: Information Circular IC 68, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 p
    Overbeck, J.R., Buzard, R.M., Turner, M.M., Miller, K.Y., and Glenn, R.J., 2020, Shoreline change at Alaska coastal communities: Report of Investigation RI 2020-10, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 29 p., 47 sheets
    Overbeck, J.R., Kennedy, Katrina, and Heim, Rebecca, 2017, Color-indexed elevation maps for flood-vulnerable coastal communities in western Alaska: Miscellaneous Publication MP 154 v. 2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 23 p., 36 sheets
    Smith, J.R., Gray, Glenn, and Kinsman, N.E.M., 2012, Annotated bibliography series in support of coastal community hazard planning - northwest Alaska: Miscellaneous Publication MP 147, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 5 p

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

  1. How well have the observations been checked?
    The accuracy of observations may vary by collection method and/or source. DGGS staff performed visual qualitative assessments of all data to ensure reasonableness and, where possible, quantitative comparisons. Horizontal and vertical accuracy are included as attributes of individual points in the Profile Points feature class.
  2. How accurate are the geographic locations?
    Horizontal point location accuracy is highly dependent on the data-collection method. For DGPS data, horizontal accuracies are reported as the Root Mean Square (RMS) error of the post-processed positions (typically less than 10cm). For DEM-derived profile elevation data, the horizontal positional accuracy depends on the point data's ground spacing. For elevation profiles obtained with various types of differential leveling techniques, the geographic accuracy of the entire profile location (approximately 10 cm to 1 km) is much poorer than the relative horizontal accuracy of the individual elevation points along each profile. Every effort has been made to infer appropriate horizontal accuracy for these varying methodologies based on all available information associated with the original data set.
  3. How accurate are the heights or depths?
    Vertical point location accuracy is highly dependent on the data-collection method. For DGPS data, vertical accuracies are reported as the Root-Mean-Square (RMS) error of the post-processed positions (typically less than 10 cm). For DEM-derived profile elevation data, vertical positional accuracy depends on the reported vertical accuracy of the underlying data source. For elevation profiles obtained with various types of differential leveling techniques, the vertical accuracy of the entire profile location (approximately 10 cm to 1 m) is much poorer than the relative horizontal accuracy of the individual elevation points along each profile. Every effort has been made to infer appropriate vertical accuracies for these varying methodologies based on all available information associated with the original data set.
  4. Where are the gaps in the data? What is missing?
    For this version 2 release, DGGS integrated previously stored data with post-update acquisitions and reprocessed the data to improve the reliability of comparative analyses and the precision of future datasets. The database will be updated as new data become available, ensuring that derived products evolve. Its open-access design encourages broad participation in community-based coastal monitoring and fosters a deeper understanding of shoreline change across the state.
  5. How consistent are the relationships among the observations, including topology?
    Gaps in profile data exist when DGPS points fail to post-process. This is generally due to receiver malfunctions or fewer observed satellites. When viewing profile elevation data, these gaps typically appear as unsampled sections. Older data, especially DGPS acquisitions, are generally less precise in adherence to individual profile geometry because these surveys were typically performed without the aid of defined profile transects to stake out. Newer data (typically post-2020) are more consistent with the profile geometry to which they are related. However, moderate imprecision remains possible, even with the aid of a defined profile transect.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints:
This report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).
Use_Constraints:
Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
  1. Who distributes the data set? (Distributor 1 of 1)
    State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys
    3354 College Road
    Fairbanks, AK
    USA

    907-451-5020 (voice)
    907-451-5050 (FAX)
    dggspubs@alaska.gov
    Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays
    Contact_Instructions:
    Please view our website (http://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible.
  2. What's the catalog number I need to order this data set? DDS 7 v.2
  3. What legal disclaimers am I supposed to read?
    The State of Alaska makes no express or implied warranties (including warranties of merchantability and fitness) with respect to the character, function, or capabilities of the electronic services or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity, whether from the use of the electronic services or products, any failure thereof, or otherwise, and in no event will the State of Alaska's liability to the requestor or anyone else exceed the fee paid for the electronic service or product.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 15-Dec-2025
Metadata author:
Simone Montayne
3354 College Road
Fairbanks, AK
USA

907-451-5020 (voice)
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:
Generated by mp version 2.9.50 on Mon Dec 15 14:01:13 2025