Metadata: Identification_Information: Citation: Citation_Information: Originator: Alexander L. Nereson Originator: Ann E. Gibbs Originator: Li H. Erikson Publication_Date: 20260313 Title: Topobathymetric digital elevation model of Little Diomede Island, Alaska, 2010 to 2021 Geospatial_Data_Presentation_Form: raster digital data Series_Information: Series_Name: data release Issue_Identification: DOI: 10.5066/P13BXTXV Publication_Information: Publication_Place: Pacific Coastal and Marine Science Center, Santa Cruz, California Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.5066/P13BXTXV Larger_Work_Citation: Citation_Information: Originator: Alexander L. Nereson Originator: Ann E. Gibbs Originator: Li H. Erikson Publication_Date: 2025 Title: Topobathymetric digital elevation models – coastal Alaska Geospatial_Data_Presentation_Form: raster digital data Publication_Information: Publication_Place: Pacific Coastal and Marine Science Center, Santa Cruz, California Publisher: U.S. Geological Survey Other_Citation_Details: Suggestion citation: Nereson, A.L., Gibbs, A.E., and Erikson, L.H., 2025, Topobathymetric digital elevation models – coastal Alaska: U.S. Geological Survey data release, https://doi.org/10.5066/P13BXTXV. Online_Linkage: https://doi.org/10.5066/P13BXTXV Description: Abstract: This dataset contains a 1-meter resolution, seamless topobathymetric digital elevation model (TBDEM) and associated spatial metadata for Little Diomede Island, Alaska. The TBDEM contains best available multi-source topographic and bathymetric elevation data collected between the years 2010 and 2021. Processing was done by the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC) and results are provided as a Cloud Optimized GeoTIFF (COG). Purpose: This product was created to help advance coastal storm response and recovery in Alaskan coastal communities in the wake of the September 2022 extratropical Typhoon Merbok disaster. It is being used by the USGS to support the development of dynamic flood models for more than 20 communities along the northwest coasts of Alaska. This product is intended for reuse by scientists, managers, and the general public. These data can be opened with most geographic information systems (GIS) software for data visualization and analysis purposes. Supplemental_Information: Work was funded by Title VII of Division N in the Consolidated Appropriations Act, 2023 (Public Law 117–328) to support direct recovery and rebuilding decisions in the wake of declared disasters related to hurricanes and typhoons in 2022. For more information on these efforts, see https://www.usgs.gov/supplemental-appropriations-for-disaster-recovery-activities/typhoon-merbok-coastal-community. 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, this metadata file may include some vendor-specific terminology. 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. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2010 Ending_Date: 2021 Currentness_Reference: ground condition at the time source data were collected Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -168.97069 East_Bounding_Coordinate: -168.87446 North_Bounding_Coordinate: 65.77505 South_Bounding_Coordinate: 65.73467 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:ae1f2409-62eb-47d6-98a8-76be0e0717dc Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: elevation Theme: Theme_Keyword_Thesaurus: Data Categories for Marine Planning Theme_Keyword: Bathymetry and Elevation Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: topography Theme_Keyword: bathymetry Theme_Keyword: digital elevation models Theme_Keyword: geospatial datasets Theme: Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) Theme_Keyword: coast Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: U.S. Geological Survey Theme_Keyword: USGS Theme_Keyword: Coastal and Marine Hazards and Resources Program Theme_Keyword: CMHRP Theme_Keyword: Pacific Coastal and Marine Science Center Theme_Keyword: PCMSC Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: State of Alaska Place_Keyword: Nome Census Area Place_Keyword: Little Diomede Island Place_Keyword: City of Diomede Place_Keyword: Bering Strait Place_Keyword: Chukchi Sea Place_Keyword: Bering Sea Access_Constraints: No access constraints 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. This information is not intended for navigation purposes. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: PCMSC Science Data Coordinator Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Address: Address_Type: mailing and physical Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-427-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Browse_Graphic: Browse_Graphic_File_Name: diomede_browse.png Browse_Graphic_File_Description: Quick view image of seamless topobathymetric digital elevation model for Little Diomede Island, Alaska Browse_Graphic_File_Type: PNG Native_Data_Set_Environment: Global Mapper v25.0 and ArcGIS Pro 3.4 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: No formal attribute accuracy tests were conducted. Logical_Consistency_Report: Quality checks were performed on the elevation raster and spatial metadata files, including review of minimum/maximum elevation values, shoreline positions, gridding artifacts, and descriptive attributes. Data values fall within expected ranges. Completeness_Report: Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The horizontal accuracy of the final seamless TBDEM was not assessed quantitatively. Please refer directly to the elevation data sources for measures of accuracy and uncertainty, when available. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The authors calculated the mean bias error (MBE) and root mean square error (RMSE) of the final, seamless TBDEM relative to the check point subsets for Little Diomede Island, Alaska. The MBE (TBDEM minus all check points) is 0.000 m and the RMSE 0.093 m. For other measures of vertical accuracy, please refer directly to the metadata for each data source cited below. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: U.S. Army Corps of Engineers (USACE) Joint Airborne Lidar Bathymetry Technical Center of eXpertise (JALBTCX) Publication_Date: 2024 Title: 2019 USACE NCMP Topobathy Lidar DEM: Alaska Geospatial_Data_Presentation_Form: raster digital data Publication_Information: Publication_Place: online Publisher: NOAA Office for Coastal Management Online_Linkage: https://www.fisheries.noaa.gov/inport/item/59419 Type_of_Source_Media: Digital and/or Hardcopy Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2019 Source_Currentness_Reference: ground condition at time data were collected Source_Citation_Abbreviation: 2019 USACE NCMP tblidar Source_Contribution: Elevations in this data source were used with the other source data to interpolate a seamless topobathymetric digital elevation model. Source_Information: Source_Citation: Citation_Information: Originator: Office of Coast Survey, National Ocean Service, NOAA, U.S. Department of Commerce Publication_Date: 2014 Title: H12229: NOS Hydrographic Survey, Bering Strait and Vicinity, 2010-08-29 Geospatial_Data_Presentation_Form: raster digital data Publication_Information: Publication_Place: online Publisher: NOAA National Centers for Environmental Information Online_Linkage: https://www.ngdc.noaa.gov/nos/H12001-H14000/H12229.html Type_of_Source_Media: Digital and/or Hardcopy Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2010 Source_Currentness_Reference: ground condition at time data were collected Source_Citation_Abbreviation: 2010 NOS multibeam Source_Contribution: Elevations in this data source were used with the other source data to interpolate a seamless topobathymetric digital elevation model. Source_Information: Source_Citation: Citation_Information: Originator: Claire Porter Originator: Ian Howat Originator: Myoung-Jon Noh Originator: Erik Husby Originator: Samuel Khuvis Originator: Evan Danish Originator: Karen Tomko Originator: Judith Gardiner Originator: Adelaide Negrete Originator: Bidhyananda Yadav Originator: James Klassen Originator: Cole Kelleher Originator: Michael Cloutier Originator: Jesse Bakker Originator: Jeremy Enos Originator: Galen Arnold Originator: Greg Bauer Originator: Paul Morin Publication_Date: 2023 Title: ArcticDEM, Version 4.1 Geospatial_Data_Presentation_Form: raster digital data Publication_Information: Publication_Place: online Publisher: Polar Geospatial Center, University of Minnesota Online_Linkage: https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/3VDC4W Online_Linkage: https://www.pgc.umn.edu/data/arcticdem/ Type_of_Source_Media: Digital and/or Hardcopy Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2011 Ending_Date: 2021 Source_Currentness_Reference: ground condition at time data were collected Source_Citation_Abbreviation: PGC ArcticDEM v 4.1 Source_Contribution: Elevations in this data source were used with the other source data to interpolate a seamless topobathymetric digital elevation model. Source_Information: Source_Citation: Citation_Information: Originator: U.S. Army Corps of Engineers, Alaska District Publication_Date: 2013 Title: LITTLE DIOMEDE, ALASKA CIVIL TOPOGRAPHIC/HYDROGRAPHIC SURVEY, AUGUST 19 - 29, 2012 and JULY 10 - 23, 2013 Geospatial_Data_Presentation_Form: tabular digital data Publication_Information: Publication_Place: by request Publisher: U.S. Army Corps of Engineers, Alaska District Online_Linkage: https://www.poa.usace.army.mil/Portals/34/docs/civilworks/currentproj/DiomedeFeasibilityReport06022014.pdf Type_of_Source_Media: Digital and/or Hardcopy Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2012 Source_Currentness_Reference: ground condition at time data were collected Source_Citation_Abbreviation: 2012 USACE sonar Source_Contribution: Elevations in this data source were used with the other source data to interpolate a seamless topobathymetric digital elevation model. Source_Information: Source_Citation: Citation_Information: Originator: National Oceanic and Atmospheric Administration (NOAA) Publication_Date: 2024 Title: NOAA Tides and Currents Publication_Information: Publication_Place: online Publisher: National Oceanic and Atmospheric Administration (NOAA) Online_Linkage: https://tidesandcurrents.noaa.gov/ Type_of_Source_Media: online database Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2024 Source_Currentness_Reference: date data were accessed Source_Citation_Abbreviation: conversion constant Source_Contribution: Local conversion constants Source_Information: Source_Citation: Citation_Information: Originator: Alaska Department of Natural Resources Publication_Date: 2024 Title: Alaska Tidal Datum Portal Publication_Information: Publication_Place: online Publisher: Alaska Department of Natural Resources Online_Linkage: https://dggs.alaska.gov/hazards/coastal/ak-tidal-datum-portal.html Type_of_Source_Media: online database Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2024 Source_Currentness_Reference: date data were accessed Source_Citation_Abbreviation: conversion constant Source_Contribution: Local conversion constants Process_Step: Process_Description: Define an area of interest (AOI) and gather published topographic and bathymetric elevation datasets with coverage in the AOI. Process_Date: 20240911 Process_Step: Process_Description: View and prioritize source elevation datasets based on date of acquisition, spatial distribution, accuracy, and point density. In general, more recent dates of acquisition, wider spatial distribution, higher accuracy, and higher point density result in a higher priority level. Source elevation datasets are listed in their order of priority in the Lineage section of this metadata file and in the associated spatial metadata, where the first source dataset is of the highest priority. Source_Used_Citation_Abbreviation: 2019 USACE NCMP tblidar Source_Used_Citation_Abbreviation: 2010 NOS multibeam Source_Used_Citation_Abbreviation: PGC ArcticDEM v 4.1 Source_Used_Citation_Abbreviation: 2012 USACE sonar Process_Date: 20240911 Process_Step: Process_Description: Prepare each source elevation dataset, as applicable. In Global Mapper software: A) transform the source dataset from its native horizontal and vertical spatial reference systems to the appropriate NAD83 (2011) Universal Transverse Mercator (UTM) zone projection and to NAVD88 GEOID12B, respectively. Convert source elevations to NAVD88 by adding a local conversion constant to the native tidal/ellipsoidal heights of the source dataset. Conversion constants used for this work come from NOAA Tides and Currents (https://tidesandcurrents.noaa.gov/) or the Alaska Tidal Datum Portal (https://dggs.alaska.gov/hazards/coastal/ak-tidal-datum-portal.html) for the most recent available tidal epoch for the tide station nearest to the AOI. The local constants used for this project are listed in the last process step of this metadata file, along with any additional transformations that may have been used bring source datasets into NAVD88 GEOID12B. B) Save the transformed dataset as a LAZ point file. C) Clip LAZ point file to AOI polygon. D) Classify and remove non-ground points from structure-from-motion (SfM)-derived digital surface models (DSMs) using lidar auto-classification. E) Spatially thin LAZ file to one-meter resolution, using the minimum value method. F) Clip the LAZ file to all higher-priority datasets using a buffer of 2x the average point density/resolution of the source dataset being prepared. G) Split the LAZ file into two subsets, one containing 95 percent of the points (active points) and the other containing the remaining 5 percent, or every 20th point (check points). The active points are later gridded in the elevation model along with associated interpolation guides to derive the final topographic surface, while the check points are used to compute the interpolation accuracy of the derived surface. Source_Used_Citation_Abbreviation: conversion constant Process_Date: 20241201 Process_Step: Process_Description: Create interpolation guides. Interpolation guides are author-defined 3D points, lines, or polygons used to help derive the final topographic surface. Interpolation guides are used to A) smooth or accentuate breaks in slope along shared boundaries of source datasets, B) prevent topographic creep/shoreline migration from onshore regions into offshore regions, C) fill data gaps in source datasets with plausible heights when local knowledge, qualitative field observations, remotely sensed optical imagery, or other information sources are available, or D) otherwise facilitate the seamless integration of all source datasets. Details of interpolation guides used to create the final elevation surface for this release are listed in the last process step of this metadata file. Process_Date: 20241212 Process_Step: Process_Description: Interpolate a one-meter resolution seamless elevation surface from input source data and interpolation guides using the Create Elevation Grid tool (triangulation method). Process_Date: 20241212 Process_Step: Process_Description: Export grid as a Cloud Optimized GeoTIFF (COG) using Global Mapper, clipping the grid bounds to the project AOI and snapping the output raster cells to the appropriate UTM zone projection, using a bilinear resampling method. Process_Date: 20241213 Process_Step: Process_Description: Quantify interpolation error in MATLAB by calculating the mean bias error (MBE) and root mean square error (RMSE) of the final, seamless TBDEM relative to the check point subsets. MBE and RMSE are reported in the Vertical Positional Accuracy section of this metadata file. Process_Date: 20241213 Process_Step: Process_Description: Create spatial metadata for each source dataset by converting LAZ points to simplified bounding polygons and save in an Esri file geodatabase feature class, along with descriptive attributes about the source dataset. Spatial metadata files are further described in the Entity and Attribute Overview section of this metadata file. Process_Date: 20241213 Process_Step: Process_Description: Perform quality checks on the output elevation raster and spatial metadata files, including review of minimum/maximum elevation values, shoreline positions, gridding artifacts, and descriptive attributes. Process_Date: 20241214 Process_Step: Process_Description: Metadata was modified to bring up to current USGS standards. The keyword geospatial datasets was added. No data information was changed. Process_Date: 20260305 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Manda Au Contact_Organization: U.S. Geological Survey Contact_Position: Data Management Specialist Contact_Address: Address_Type: Mailing Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-460-7575 Contact_Electronic_Mail_Address: mau@usgs.gov Process_Step: Process_Description: Special considerations: A) Vertical datum conversion constants: 0 m NAVD88 is -0.81 m above Mean Lower Low Water (at NOAA CO-OPS tide station: 9469439, Tin City, Bering Sea, via Alaska Tidal Datum Portal). B) Additional vertical transformations: PGC ArcticDEM v 4.1 exhibited a systematic offset (tilting) in areas of overlap with 2019 USACE NCMP tblidar (a higher priority dataset). The systematic offset was characterized and compensated for in the vertical transformation step by calculating the difference between ArcticDEM v 4.1 and 2019 USACE NCMP tblidar in areas of overlap, running a global polynomial interpolation (Order 1) of the differences in Esri ArcGIS Pro to create a correction surface, and adding the values in the correction surface to the values of PGC ArcticDEM v 4.1. C) Interpolation guides: 2019 USACE NCMP tblidar was clipped in the vicinity of the boat landing south of the heliport to remove a DEM artifact and interpolation guides (author-defined points elevations) were inserted to prevent topographic creep in the final elevation surface. Source_Used_Citation_Abbreviation: conversion constant Process_Date: 20241214 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 4363 Column_Count: 4268 Vertical_Count: 1 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 2 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 Longitude_of_Central_Meridian: -171.0 Latitude_of_Projection_Origin: 0.0 False_Easting: 500000.0 False_Northing: 0.0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: row and column Coordinate_Representation: Abscissa_Resolution: 1.0 Ordinate_Resolution: 1.0 Planar_Distance_Units: meters Geodetic_Model: Horizontal_Datum_Name: NAD83_National_Spatial_Reference_System_2011 Ellipsoid_Name: GRS 1980 Semi-major_Axis: 6378137.0 Denominator_of_Flattening_Ratio: 298.257222101004 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: North American Vertical Datum of 1988 (NAVD88) Altitude_Resolution: 0.001 Altitude_Distance_Units: meters Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: diomede_tbdem_1m_2010-2021.tif Entity_Type_Definition: Raster geospatial data file. Entity_Type_Definition_Source: Producer Defined Attribute: Attribute_Label: Elevation Attribute_Definition: Orthometric height in meters NAVD88 (GEOID12B). Values of -9999 = no data. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: -9999 Enumerated_Domain_Value_Definition: no data Enumerated_Domain_Value_Definition_Source: Producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -46.440 Range_Domain_Maximum: 397.732 Attribute_Units_of_Measure: meters Attribute_Measurement_Resolution: 0.001 Overview_Description: Entity_and_Attribute_Overview: These metadata describe a Cloud Optimized GeoTIFF (COG) raster file whose floating point grid cell values represent orthometric heights (elevations) in meters NAVD88 GEOID12B. The file name for the elevation raster follows the format: “location_tbdem_1m_YYYY_to_YYYY.tif”, where “location” is the geographic name of the place depicted in the data, “tbdem” indicates “topobathymetric digital elevation model”, “1m” indicates 1-meter grid resolution, and “YYYY_to_YYYY” indicates the date range (in years) of all the source data. The source data are further described in a supplementary "spatial" metadata file that contains polygonal boundaries and descriptive attributes for each source. Polygons and attributes are saved as a feature class in an Esri file geodatabase with a file name that follows the naming convention described above, along with the following suffix: "_spatial_metadata.gdb". The file geodatabase has been compressed into a ZIP file of the same name. The following attribute fields are included in the polygon feature class: Name of dataset (Title), the organization major project or activity (Source_Project), source dataset organization (Source_Organization), date(s) acquired (Date_Acquired), publication date (Publication Date), source elevation type (Data_Type), source projection (Source_Projection), source horizontal resolution (Source_Horizontal_Resolution), source horizontal datum (Source_Horizontal_Datum), source vertical units (Source_Vertical_Units), source vertical datum (Source_Vertical_Datum), source geoid (Geoid), spatial extent of source (Coverage_Area), source URL (Source_Publication), perimeter of polygon feature in meters (Shape_Length), and area of polygon feature in square meters (Shape_Area). Descriptive attributes for interpolation guides are set to Null. See Process Steps above for more information on how and where guides were created. Entity_and_Attribute_Detail_Citation: U.S. Geological Survey Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - CMGDS Contact_Address: Address_Type: mailing and physical Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-427-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Resource_Description: These data are available in Cloud Optimized GeoTIFF (COG) raster file format accompanied by a spatial metadata geodatabase file and CSDGM FGDC-compliant metadata. Distribution_Liability: 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 for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: GeoTIFF Format_Version_Number: Global Mapper v25.0 and ArcGIS Pro 3.4 Format_Information_Content: Cloud Optimized GeoTIFF (COG) raster file whose floating point grid cell values represent orthometric heights (elevations). No data value is -9999. File_Decompression_Technique: No compression applied. Transfer_Size: 50 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://doi.org/10.5066/P13BXTXV Access_Instructions: Data and metadata can be downloaded using the Network_Resource_Name link and scrolling down to the Topobathymetric digital elevation model of Little Diomede Island, Alaska, 2010 to 2021 section. Fees: None Technical_Prerequisites: Most geospatial data software and their supporting operating systems (for example, QGIS, Global Mapper, Esri ArcGIS Pro, or similar). Metadata_Reference_Information: Metadata_Date: 20260313 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Person: PCMSC Science Data Coordinator Contact_Address: Address_Type: mailing and physical Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-427-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998