Alaska merged geophysical data grids

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Frequently anticipated questions:


What does this data set describe?

Title: Alaska merged geophysical data grids
Abstract:
Merged grids of residual magnetic intensity and apparent resistivity compiled from the Beaver Creek, Fox Hills, Southern Dishna River, Aniak, Sleetmute, Iditarod geophysical surveys.
Supplemental_Information:
idi_ani_slt_bvc_fxh_sdr: Geosoft-format binary grids, GeoTiff format gridded data images, KMZ/KML files, Geosoft ASCII polygon files (PLY), Geosoft ASCII zone files, ESRI Shapefiles, and ERMapper files. Note: these data are provided in both UTM Zone 4 - NAD27 and Geographic WGS84 projections. The data files were compiled from the Beaver Creek, Fox Hills, Southern Dishna River, Aniak, Sleetmute, Iditarod geophysical surveys.
  1. How should this data set be cited?

    Staff, DGGS, 2016, Alaska merged geophysical data grids: Digital Data Series DDS 12, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -159.363394
    East_Bounding_Coordinate: -156.204523
    North_Bounding_Coordinate: 63.171061
    South_Bounding_Coordinate: 61.484406

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 2000
    Ending_Date: 2013
    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 North American Datum of 1927.
      The ellipsoid used is Clarke 1866.
      The semi-major axis of the ellipsoid used is 6378206.40000000037.
      The flattening of the ellipsoid used is 1/294.978698199999997.

  7. How does the data set describe geographic features?

    idi_ani_slt_bvc_fxh_sdr
    Geosoft-format binary grids, GeoTiff format gridded data images, KMZ/KML files, Geosoft ASCII polygon files (PLY), Geosoft ASCII zone files, ESRI Shapefiles, and ERMapper files. Note: these data are provided in both UTM Zone 4 - NAD27 and Geographic WGS84 projections. The data files were compiled from the Beaver Creek, Fox Hills, Southern Dishna River, Aniak, Sleetmute, Iditarod geophysical surveys. (Source: Alaska Division of Geological & Geophysical Surveys (DGGS) and contractor.)


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?

    Funding for this geophysical survey data compilation was provided by U.S. Bureau of Land Management, Alaska Division of Geological & Geophysical Surveys' (DGGS) Airborne Geophysical/Geological Mineral Inventory (AGGMI) program, and the Alaska Strategic and Critical Minerals Assessment Capital Improvement Project. The geophysical surveys were managed by State of Alaska, Department of Natural Resources (DNR), Division of Geological & Geophysical Surveys (DGGS). The survey data were collected, processed, and/or managed by Burns, Laurel E., Stephens, Mark, Stevens Exploration Management Corp., Fugro Airborne Surveys Corp., Fugro GeoServices, Inc., CGG, Emond, A.M., Barefoot, J.B., and Graham, G.R.C. These merged grids were generated as part of the Fox Hills data collection contract.

  3. To whom should users address questions about the data?

    Alaska Division of Geological & Geophysical Surveys
    Metadata Manager
    3354 College Road
    Fairbanks, AK 99709-3707
    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


Why was the data set created?

This electromagnetic and magnetic airborne geophysical survey data compilation is a product of the Alaska Division of Geological & Geophysical Surveys' (DGGS) Airborne Geophysical/Geological Mineral Inventory (AGGMI) program and the Alaska Strategic and Critical Minerals Assessment Capital Improvement Project. The goal of the Alaska Division of Geological & Geophysical Surveys' (DGGS) Airborne Geophysical/Geological Mineral Inventory (AGGMI) program is to enhance the understanding of Alaska's mineral resources and stimulate private-sector mineral development. The program seeks to delineate mineral zones on Alaska State lands that: (1) have major economic value; (2) can be developed in the short term to provide high-quality jobs for Alaskans; and (3) will provide economic diversification to help offset the loss of Prudhoe Bay oil revenue. Candidate lands for this program are identified on the basis of existing geologic knowledge, land ownership, and nominations from Alaska's geologic community. The AGGMI program and resulting new geologic knowledge are recognized worldwide and have encouraged millions of dollars of venture capital expenditures in the local economies of the surveyed mining districts. These venture capital expenditures have led to discovery and delineation of new mineral resources. The multi-year Strategic and Critical Minerals Assessment Capital Improvement Project (SCMA) was established to determine Alaska's geologic potential for rare-earth elements and other minerals that are essential for our modern, technology-based society. This program began in FY2012 with a data survey and compilation of existing information on rare-earth-element occurrences in Alaska, and expanded significantly in FY2013 to include additional critical minerals, re-analyses of existing samples, and obtaining new field and analytical data, including airborne geophysics.


How was the data set created?

  1. From what previous works were the data drawn?

    Burns, L.E., 2000 (source 1 of 32)
    Burns, L.E., 2000, Portfolio of aeromagnetic and resistivity maps of parts of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-41, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 18 p
    Type_of_Source_Media: paper
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 2 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, 7200 Hz coplanar resistivity of parts of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-31, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 sheets, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 3 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, 7200 Hz coplanar resistivity of parts of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-32, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 sheets, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 4 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, 7200 Hz coplanar resistivity of parts of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-33, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 sheets, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 5 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, 900 Hz coplanar resistivity of parts of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-34, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 sheets, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 6 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, 900 Hz coplanar resistivity of parts of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-35, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 sheets, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 7 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, 900 Hz coplanar resistivity of parts of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-36, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 sheets, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 8 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, CD-ROM containing gridded data, vector data, and location information of 2000 geophysical survey data for parts of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-39, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Type_of_Source_Media: paper
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 9 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, Color shadow magnetic map of part of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-27, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 sheets, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 10 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, DVD containing profile data, gridded data, vector data, and location information of 2000 geophysical survey data for parts of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-38, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 DVD
    Type_of_Source_Media: paper
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 11 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, Flight lines of parts of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-37, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 sheets, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 12 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, Total magnetic field and detailed electromagnetic anomalies of parts of the Aniak and Iditarod mining districts, southwestern Alaska, (parts of the Iditarod A-4 and A-5 quadrangles): Geophysical Report GPR 2000-30D, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:31,680
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 31680
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 13 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, Total magnetic field and detailed electromagnetic anomalies of parts of the Aniak and Iditarod mining districts, southwestern Alaska, (parts of the Iditarod A-5 and A-6 quadrangles): Geophysical Report GPR 2000-30C, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:31,680
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 31680
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 14 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, Total magnetic field and detailed electromagnetic anomalies of parts of the Aniak and Iditarod mining districts, southwestern Alaska, (parts of the Iditarod B-4 and B-5 quadrangles): Geophysical Report GPR 2000-30B, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:31,680
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 31680
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 15 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, Total magnetic field and detailed electromagnetic anomalies of parts of the Aniak and Iditarod mining districts, southwestern Alaska, (parts of the Iditarod B-5 and B-6 quadrangles): Geophysical Report GPR 2000-30A, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:31,680
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 31680
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 16 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, Total magnetic field and detailed electromagnetic anomalies of parts of the Aniak and Iditarod mining districts, southwestern Alaska, part of the Sleetmute C-6 quadrangle: Geophysical Report GPR 2000-30H, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:31,680
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 31680
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 17 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, Total magnetic field and detailed electromagnetic anomalies of parts of the Aniak and Iditarod mining districts, southwestern Alaska, part of the Sleetmute C-7 quadrangle: Geophysical Report GPR 2000-30G, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:31,680
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 31680
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 18 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, Total magnetic field and detailed electromagnetic anomalies of parts of the Aniak and Iditarod mining districts, southwestern Alaska, part of the Sleetmute D-6 quadrangle: Geophysical Report GPR 2000-30F, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:31,680
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 31680
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 19 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, Total magnetic field and detailed electromagnetic anomalies of parts of the Aniak and Iditarod mining districts, southwestern Alaska, part of the Sleetmute D-7 quadrangle: Geophysical Report GPR 2000-30E, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:31,680
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 31680
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 20 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, Total magnetic field and electromagnetic anomalies of parts of the Aniak and Iditarod mining districts, southwestern Alaska (clear mylar version): Geophysical Report GPR 2000-28, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Type_of_Source_Media: paper
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 21 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, Total magnetic field and electromagnetic anomalies of parts of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-29, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 sheets, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 22 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, Total magnetic field of parts of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-25, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 sheets, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2000 (source 23 of 32)
    Burns, L.E., Stevens Exploration Management Corp., Surveys, Fugro Airborne, and U.S. Bureau of Land Management, 2000, Total magnetic field of parts of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-26, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 sheets, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

    Stephens, Mark and Fugro Airborne Surveys, 2000 (source 24 of 32)
    Stephens, Mark, and Surveys, Fugro Airborne, 2000, Project report of the geophysical survey of parts of the Aniak and Iditarod mining districts, southwestern Alaska: Geophysical Report GPR 2000-40, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 240 p., 2 sheets, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2011 (source 25 of 32)
    Burns, L.E., Fugro Airborne Surveys Corp., and Fugro GeoServices, Inc., 2011, Iditarod survey area: Magnetic and electromagnetic line, grid, and vector data and maps, Innoko, Iditarod, and McGrath mining districts, Iditarod and Ophir quadrangles, western Alaska: Geophysical Report GPR 2011-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 39 sheets, scale 1:63,360, 1 DVD
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2015 (source 26 of 32)
    Burns, L.E., Fugro Airborne Surveys Corp., and Fugro GeoServices, Inc., 2015, Iditarod survey area: Airborne magnetic and electromagnetic data in line, grid, vector, and map formats, and descriptive project report, Innoko, Iditarod, and McGrath mining districts, Iditarod and Ophir quadrangles, western Alaska: Geophysical Report GPR 2011-4, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 12 sheets
    Type_of_Source_Media: paper
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2003 (source 27 of 32)
    Burns, L.E., U.S. Bureau of Land Management, Surveys, Fugro Airborne, and Stevens Exploration Management Corp., 2003, Line, grid, and vector data of the airborne geophysical survey data of the Sleetmute area, southwestern Alaska: Geophysical Report GPR 2003-10, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 DVD
    Type_of_Source_Media: paper
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2003 (source 28 of 32)
    Burns, L.E., U.S. Bureau of Land Management, Surveys, Fugro Airborne, and Stevens Exploration Management Corp., 2003, Plot files of the airborne geophysical survey data of the Sleetmute area, southwestern Alaska: Geophysical Report GPR 2003-9, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 DVD
    Type_of_Source_Media: paper
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2003 (source 29 of 32)
    Burns, L.E., U.S. Bureau of Land Management, Surveys, Fugro Airborne, and Stevens Exploration Management Corp., 2003, Portfolio of aeromagnetic and resistivity maps of the Sleetmute area, southwestern Alaska: Geophysical Report GPR 2003-12, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Type_of_Source_Media: paper
    Source_Contribution: Data collection, processing, and delivery

    Stephens, Mark and Fugro Airborne Surveys, 2003 (source 30 of 32)
    Stephens, Mark, and Surveys, Fugro Airborne, 2003, Project report of the airborne geophysical survey of the Sleetmute area, southwestern Alaska: Geophysical Report GPR 2003-11, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 211 p., 2 sheets, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2015 (source 31 of 32)
    Burns, L.E., CGG, and Fugro GeoServices, Inc., 2015, Project report, interpretation maps, EM anomalies, stacked multi-channel profiles, and other products of the airborne geophysical survey for the southern Dishna River, Fox Hills, and Beaver Creek survey areas, Iditarod, Ophir, and Holy Cross quadrangles, western Alaska: Geophysical Report GPR 2014-3, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 126 sheets, 1 DVD
    Type_of_Source_Media: paper
    Source_Contribution: Data collection, processing, and delivery

    Burns, L.E. and others, 2013 (source 32 of 32)
    Burns, L.E., Fugro Airborne Surveys Corp., and Fugro GeoServices, Inc., 2013, Southern Dishna River, Fox Hills, and Beaver Creek survey areas: Airborne Magnetic and electromagnetic data in line (point), grid, vector, and map formats, Iditarod, Ophir, and Holy Cross quadrangles, western Alaska: Geophysical Report GPR 2013-1, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: scale 1:63,360, 1 DVD
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Data collection, processing, and delivery

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

    Date: 2013 (process 1 of 3)
    Gridded data - The gridded data from the Beaver Creek, Fox Hills, Southern Dishna River, Aniak, Sleetmute, Iditarod geophysical surveys were merged with previously created merged grids from the older surveys, Iditarod, Aniak and Sleetmute survey blocks, using Oasis Montaj techniques. A merge of the residual magnetic data was possible for all areas. The Beaver Creek, Fox Hills, Southern Dishna River, and Iditarod diurnally corrected data were adjusted for regional variations, i.e. IGRF gradient, 2010, updated to the date of data acquisition and adjusted for altimeter variations on a point by point basis. The older surveys, Aniak and Sleetmute, would have been adjusted for regional variations based on the IGRF of a single point in the middle of the survey area, and a single height and date. The residual grids of all the areas may therefore have different base values dependent on the IGRF model used because of the time elapsed between the flying of the first and last surveys. The grids were adjusted to each other prior to the final merge. The apparent resistivity grids for 56,000 Hz, 7200 Hz, and 900 Hz coplanar EM data were merged with no reprocessing, as general processing methods and more importantly background resistivity values for all frequencies have not changed since the original merge of the Aniak and Sleetmute data in 2003. Oasis Montaj has the capability to merge or stitch two or three grids together. The process requires overlap between adjacent grid areas. There is also the option of selecting different grid stitch techniques. For this project the standard "Suture" technique with the 'No De-trending' option was selected. The process requires selecting a "master" grid or the grid that all other grids will be levelled to. The grid that was published first is usually chosen and the grid from the most recent survey was selected as the secondary grid (i.e. the grid that will be DC shifted to the master grid). .

    Date: 2017 (process 2 of 3)
    Boundary - DGGS staff constructed a boundary of the merged grid file. The grid boundary was constructed using Geosoft Oaisis montaj grid outline and map export functions. The boundary file is available in Geosft PLY ASCII format and ESRI Shapefile format.

    Date: 2019 (process 3 of 3)
    Google Earth KMZ files - DGGS staff created Google Earth KMZ/KML files from the grid files data using ESRI ArcGIS software.

  3. What similar or related data should the user be aware of?

    Geological Survey of Canada, and U.S. Geological Survey, 2015, Yukon - eastern Alaska magnetic grid: Natural Resources Canada, Canada.

    Online Links:


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

  1. How well have the observations been checked?

    All originating data met contract specifications with a few exceptions due to difficult operational conditions. These exceptions did not noticeably impact data quality. Additional detail about contract specifications and operational issues can be found in the metadata of the originating surveys.

  2. How accurate are the geographic locations?

    All originating data were positioned by DGPS (Differential Global Positioning System) with an accuracy of 5 meters or better.

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    Helicopter and fixed wing geophysical surveys often have small data gaps that do not negatively impact the overall quality of the final products. Reference the metadata for each originating survey for specific details.

  5. How consistent are the relationships among the observations, including topology?

    These data originate from multiple similar geophysical surveys with different specifications. Reference the metadata of each originating survey for exact specifications.


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 99709-3707
    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
  2. What's the catalog number I need to order this data set?

    DDS 12

  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: 18-Jul-2019
Metadata author:
Alaska Division of Geological & Geophysical Surveys
Attn: Simone Montayne
Metadata Manager
3354 College Road
Fairbanks, AK 99709-3707
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 2.9.21 on Thu Jul 18 15:15:44 2019