Kuskokwim airborne electromagnetic survey, northern Kaiyuh Mountains, Alaska

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What does this data set describe?

Title:
Kuskokwim airborne electromagnetic survey, northern Kaiyuh Mountains, Alaska
Abstract:
Kuskokwim airborne electromagnetic survey, northern Kaiyuh Mountains, Alaska, Geophysical Report 2025-2, covers parts of the Nulato and Ophir quadrangles south of Galena, Alaska. Time-domain electromagnetic data were collected with the helicopter-mounted SkyTEM 306HP system from July 22 to August 19, 2024, by SkyTEM Canada Incorporated. A total of 5,823.4 line kilometers were collected over a single survey block covering 2,037 square kilometers. Two special sub-survey blocks were defined to increase data coverage of specific holdings: the North Block--funded in collaboration with Doyon, Limited--and the South Block--funded in collaboration with Western Alaska Copper & Gold. The main survey block was flown with east-west line orientation and a nominal line spacing of 400 meters. The North Block was flown with an infilled effective line spacing of 200 meters, and the South Block was flown with an infilled effective line spacing of 200 meters, including north-south oriented lines in addition to east-west oriented lines The mean ground clearance was 45.8 +/- 10.2 meters with a nominal survey speed of 89.6 +/- 14.7 km/hr. The data were inverted to create two subsurface resistivity models, agf_sci and skytem_lci, presented herein. The data, as well as additional metadata, are available from the DGGS website: http://doi.org/10.14509/31304.
Supplemental_Information:
ascii_data:    ASCII format line data, other ASCII data	
databases_geosoft:    Geosoft format database of final line data, other Geosoft format databases	
documents:    Project report and other supporting files	
grids_geosoft:    Oasis montaj Geosoft GRD format gridded data	
grids_tif:    Geographically registered data value rasters of gridded data, GeoTiff format.	
kmz:    Keyhole markup language (kml) kmz archive files of project data. Viewable in Google Earth and other compatible programs	
maps_pdf_format:    Printable and geographically registered maps in pdf format. Compatible with mobile device navigation and desktop mapping applications.	
models_resistivity:    Files for model input parameters as well as model outputs from Aarhus Workbench. Images of resistivity sections	
vector_data:    Line path and survey boundary in ESRI shapefile (SHP) format
  1. How might this data set be cited?
    Petersen, E.I., Fusso, L.A., Emond, A.M., Incorporated, SkyTEM Canada, and Frameworks, Aqua Geo LLC, 2025, Kuskokwim airborne electromagnetic survey, northern Kaiyuh Mountains, Alaska: Geophysical Report GPR 2025-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 8 p.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -158.181948
    East_Bounding_Coordinate: -156.851936
    North_Bounding_Coordinate: 64.537548
    South_Bounding_Coordinate: 63.952806
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2024
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: digital, data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a raster data set.
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 4
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -159
      Latitude_of_Projection_Origin: 0
      False_Easting: 500000.000000
      False_Northing: 0
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest .00000001
      Ordinates (y-coordinates) are specified to the nearest .00000001
      Planar coordinates are specified in Meters
      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?
    ascii_data
    ASCII format line data, other ASCII data (Source: SkyTEM Canada Incorporated and Aqua Geo Frameworks LLC)
    databases_geosoft
    Geosoft format database of final line data, other Geosoft format databases (Source: SkyTEM Canada Incorporated and Aqua Geo Frameworks LLC)
    documents
    Project report and other supporting files (Source: SkyTEM Canada Incorporated and Aqua Geo Frameworks LLC and DGGS)
    grids_geosoft
    Oasis montaj Geosoft GRD format gridded data (Source: SkyTEM Canada Incorporated and Aqua Geo Frameworks LLC and DGGS)
    grids_tif
    Geographically registered data value rasters of gridded data, GeoTiff format. (Source: DGGS)
    kmz
    Keyhole markup language (kml) kmz archive files of project data. Viewable in Google Earth and other compatible programs (Source: DGGS)
    maps_pdf_format
    Printable and geographically registered maps in pdf format. Compatible with mobile device navigation and desktop mapping applications. (Source: SkyTEM Canada Incorporated and Aqua Geo Frameworks LLC)
    models_resistivity
    Files for model input parameters as well as model outputs from Aarhus Workbench. Images of resistivity sections (Source: DGGS)
    vector_data
    Line path and survey boundary in ESRI shapefile (SHP) format (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 supported by the State of Alaska capital improvement project funds. Doyon, Limited, and Western Alaska Copper & Gold funded additional survey lines over the North and South blocks, respectively, increasing data density in those area.
  3. To whom should users address questions about the data?
    Alaska Division of Geological & Geophysical Surveys
    Metadata Manager
    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 (https://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible.

Why was the data set created?

The data from the Kuskokwim airborne electromagnetic survey, northern Kaiyuh Mountains, Alaska, will be used to improve the understanding of geology and mineral potential and to promote resource exploration in the greater Kuskokwim Mountains region.

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: 2024 (process 1 of 2)
    Data collection, processing, and delivery - The airborne geophysical data were acquired under contract with SkyTEM Canada Incorporated and Aqua Geo Frameworks LLC. Airborne geophysical data for the areas were acquired and processed by SkyTEM Canada Incorporated and Aqua Geo Frameworks LLC. Time-domain electromagnetic data were collected with the helicopter-mounted SkyTEM 306HP system from July 22 to August 19, 2024, by SkyTEM Canada Incorporated. A total of 5,823.4 line kilometers were collected over a single survey block covering 2,037 square kilometers. Two special sub-survey blocks were defined to increase data coverage of specific holdings: the North Block--funded in collaboration with Doyon, Limited--and the South Block--funded in collaboration with Western Alaska Copper & Gold. The main survey block was flown with east-west line orientation and a nominal line spacing of 400 meters. The North Block was flown with an infilled effective line spacing of 200 meters, and the South Block was flown with an infilled effective line spacing of 200 meters, including north-south oriented lines in addition to east-west oriented lines The mean ground clearance was 45.8 +/- 10.2 meters with a nominal survey speed of 89.6 +/- 14.7 km/hr. The data were inverted to create two subsurface resistivity models, agf_sci and skytem_lci, presented herein.
    Date: 2024 (process 2 of 2)
    Data cataloged for archival and publication - Final data were published and archived by DGGS.
  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?
    Geophysical data were acquired according to the contractor, contract, and request-for-proposals specifications. For additional detail about survey parameters, see the accompanying project report available in the documents directory of this data distribution package.
  2. How accurate are the geographic locations?
    Station coordinates were positioned using a real-time or post-processed corrected differential GPS.
  3. How accurate are the heights or depths?
    Not applicable
  4. Where are the gaps in the data? What is missing?
    This data set includes files that contain processed aeromagnetic measurements, radiometric measurements, magnetic measurements, altimetry measurements, and locational data for the entire survey area. The data release is a partial release of the contractor deliverable.
  5. How consistent are the relationships among the observations, including topology?
    Data originate from one company using DGGS contract specifications for all data (see accompanying project report). The originating coordinate system was retained for all publication products.

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)
    Alaska Division of Geological & Geophysical Surveys
    Metadata Manager
    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 (https://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? GPR 2025-2
  3. What legal disclaimers am I supposed to read?
    The State of Alaska makes no expressed 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.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 24-Mar-2025
Metadata author:
Alaska Division of Geological & Geophysical Surveys
Attn: Simone Montayne
Metadata Manager
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
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 Mar 24 19:21:26 2025