{"action":"create","ckan_id":null,"date_created":"Wed, 25 Feb 2026 05:47:03 GMT","date_finished":null,"harvest_job_id":"eb09b262-e723-4298-b3a7-4ac67ebae5b1","harvest_source_id":"f4c7bbab-c7ef-4277-a7d3-c25b78854814","id":"d31778ed-48bc-44ef-8a83-9ad313648147","identifier":"https://dggs.alaska.gov/webpubs/metadata/GPR2011-4.xml","parent_identifier":null,"source_hash":"dd4731ef7a4461666638a15c074bb5f92b6387c2f7ee2ddc36e30ebcaf8585bf","source_raw":"\n\n\n\n\nBurns, L.E.\nFugro Airborne Surveys Corp.\nFugro GeoServices, Inc.\n2015\nIditarod 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\ndigital data\n\nGeophysical Report\nGPR 2011-4\n\n\nFairbanks, Alaska, United States\nAlaska Division of Geological & Geophysical Surveys\n\n12 sheets, scale 1:63,360.\nhttp://dx.doi.org/10.14509/27081\n\n\n\nThis digital publication, GPR 2011-4, contains Fugro Airborne Surveys' analysis and interpretation of data produced from airborne geophysical surveys published by DGGS in 2011 (GPR 2011-2) of the Iditarod survey area. Fugro Airborne Surveys' frequency-domain DIGHEM V system was used for the EM data. GPR 2011-4 includes (1) Fugro's project report with interpretation and detailed EM Anomalies in tabular format, (2) Multi-channel stacked profiles in pdf format, and (3) interpretation and em anomalies are each provided as Geotiffs and maps. The document gpr2011_004_readme (.txt and .pdf) lists all files included in this publication. Other supporting files include gpr2011-4_browsegraphic.pdf, gpr2011-4_emanomaly_readme.pdf. The airborne data were acquired and processed under contract between the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (DGGS), and Fugro GeoServices, Inc. Fugro Airborne Surveys, the subcontractor, acquired and processed the data in 2010 and 2011.\nThe survey was part of the Alaska Airborne Geophysical/Geological Mineral Inventory project funded by the Alaska State Legislature and managed by State of Alaska, Department of Natural Resources (DNR), Division of Geological & Geophysical Surveys (DGGS). The project seeks to catalyze private-sector mineral development investment. The project delineates 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 Alaska; and 3) will provide economic diversification to help offset the loss of Prudhoe Bay oil revenue.\n\n>geotiffs - Images on the interpretation maps and the EM anomaly map are provided as separate GeoTiff files.\n>maps_hpgl2 - hpgl2 format (.prn) maps. See gpr2011_004_readme.pdf.\n>maps_pdf - Adobe Acrobat (pdf) format maps. See gpr2011_004_readme.pdf.\n>project_report_em_anomalies - Adobe Acrobat format of Fugro Airborne Surveys' project report with interpretation EM anomaly picks for the report in csv and >Geosoft ASCII XYZ formats. File 'gpr2011-4_emanom_readme.pdf' included.\n>sm_profiles - Adobe Acrobat format of Fugro Airborne Surveys' project stacked-multi channel profile. See Project Report for more information.\n>vectors - ESRI Shape and Autocad DXF of interpretation, EM anomalies, and various locational reference files. See gpr2011_004_readme.pdf.\n\n\n\n\n\n\n2011\n\n\n2015\n\n\n\nground condition\n\n\ncomplete\nas needed\n\n\n\n-157.99\n-156.26\n63.17\n62.44\n\n\n\n\nISO 19115 Topic Category\ngeoscientificInformation\n\n\nAlaska Division of Geological & Geophysical Surveys\nAeromagnetic\nAeromagnetic Data\nAeromagnetic Map\nAeromagnetic Survey\nAirborne Geophysical / Geological Mineral Inventory\nAirborne Geophysical Survey\nApparent Resistivity Data\nApparent Resistivity Map\nApparent Resistivity Survey\nDIGHEM V EM System\nElectromagnetic Anomalies\nElectromagnetic Data\nElectromagnetic Survey\nGeophysical Survey\nGeophysics\nGeophysics Search Tag\nHEM Survey\nInterpretation\nMagnetic Survey\nMagnetics\nProject Report\nStacked Multi-Channel Profiles\n\n\nAlaska Division of Geological & Geophysical Surveys\nAlaska, State of\nIditarod Mining District\nIditarod Quadrangle\nInnoko Mining District\nMcGrath Mining District\nOphir Quadrangle\n\n\nThis 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).\nAny 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.\n\n\n\nAlaska Division of Geological & Geophysical Surveys\n\nGeophysics Staff\n\nmailing and physical\n
3354 College Road
\nFairbanks\nAK\n99709-3707\nUSA\n\n(907)451-5020\ndggsgis@alaska.gov\n8 am to 4:30 pm, Monday through Friday, except State holidays\n\n\nFunding was provided by the Alaska State Legislature for the DGGS Airborne Geophysical/Geological Mineral Inventory (AGGMI) program.\n\n\nBurns, L.E.\nFugro Airborne Surveys Corp.\nFugro GeoServices, Inc.\n2011\nIditarod survey area: Magnetic and electromagnetic line, grid, and vector data and maps, Innoko, Iditarod, and McGrath mining districts, Iditarod and Ophir quadrangles, western Alaska\n\nGeophysical Report\nGPR 2011-2\n\n\nFairbanks, Alaska, United States\nAlaska Division of Geological & Geophysical Surveys\n\n39 sheets, 1 DVD, scale 1:63,360\nhttp://dx.doi.org/10.14509/22842\n\n\n\n\n\nSurvey interpretation and documentation of data acquisition and tests done during acquisition were produced by the same company (Fugro Airborne Surveys) who acquired the data. Tests completed and constraints used are documented in the project report. Ruth Pritchard, the project report author and data interpreter, has several decades of experience interpreting aeromagnetic and electromagnetic data and making EM anomaly picks.\n\nData originate from one company using the same contract specifications for all data.\nThe data are complete.\n\n\nAccuracy of the data was discussed in the metadata for the first publication of the Iditarod survey (GPR2011-2, listed in the cross references). Other information may be included in the project report, included in the current publication. The helicopter position was derived every 0.5 seconds using post-flight differential positioning to an accuracy of better than 1 m.\n\n\nThe laser altimeter ('ALTLAS_BIRD'), located in the bird (EM equipment and magnetometer housing), had a stated resolution of 0.10 meter. The ALTLAS_BIRD value may be unreliable over bodies of water where the laser returns are scattered.\n\n\n\n\n\n\nAkima, H.\n1970\nA new method of interpolation and smooth curve fitting based on local procedures\n\nJournal of the Association of Computing Machinery\nv. 7, no. 4\n\n\nNew York, NY, USA\nAssociation for Computing Machinery\n\n\n\npaper\n\n\n\n1970\n\n\npublication date\n\nAkima, H., 1970\ninphase and quadrature components\n\n\n\n\nFraser, D.C.\n1978\nResistivity mapping with an airborne multicoil electromagnetic system\n\nGeophysics\nv. 43\n\n\nTulsa, OK, United States\nSociety of Exploration Geophysicists\n\n\n\npaper\n\n\n\n1978\n\n\npublication date\n\nFraser, D.C., 1978\ninphase and quadrature components\n\n\nInphase and quadrature components - The DIGHEM(V) EM system measured inphase and quadrature components at five frequencies. The EM system measured inphase and quadrature components at five frequencies. Two vertical coaxial-coil pairs operated at nominal frequencies of 1000 and 5500 Hz while three horizontal coplanar-coil pairs operated at 900, 7200, and 56,000 Hz. Actual frequencies for the four EM systems used in the Iditarod project report in this publication (GPR2011-4-4_ProjectReport.pdf; page 3.1). The EM data were sampled at 0.1 second intervals and interpolated onto a regular 80m grid using a modified Akima (1970) technique. The EM system responds to bedrock conductors, conductive overburden, and cultural sources. The power line monitor and the flight track video were examined to locate cultural sources. The EM anomalies that are indicated are classified by conductance. EM Anomalies are identified by creating multi-parameter stacked profiles for all survey lines at a scale of 1:31,680. Anomaly grades range from 0 to 7 and are based on calculated conductance. The grade 0 anomaly, denoted by an \"X\", indicates that in-phase and quadrature levels are below set thresholds and will not give a reliable calculation of the conductivity. These anomalies are shown with an asterisk (*) in the EM legend on the 1:31,680 scale maps (GPR2011-4-1a through GPR2011-4-2f). See Section 5 of the Project Report in this publication for more information. A copy of the original Iditarod survey and other associated files are stored at the Fugro Airborne Survey office. Rather than using the version released by DGGS in 2011 (gpr2011-2), Fugro Airborne Surveys used the files already available to them to provide data for the interpretation, EM anomaly picks, and multichannel-stacked profiles included on this publication.\nAkima, H., 1970\nFraser, D.C., 1978\n2011\n\n\nProject report and interpretation of processed geophysical data - A copy of the original Iditarod survey and other associated files are stored at the Fugro Airborne Survey office. Rather than using the version released by DGGS in 2011 (gpr2011-2), Fugro Airborne Surveys used the files already available to them to provide data for the interpretation, EM anomaly picks, and multichannel-stacked profiles included on this publication. Ruth Pritchard, a Fugro Airborne geophysicist, wrote the project report and the interpretation of the processed geophysical data. For the interpretation maps. Geologic references used in this interpretation are cited in the project report.\n2011\n\n\nGeographically registered gridded data - Geophysical images and vectors used on the EM anomaly maps were converted to GeoTIFFs using Fugro Airborne Surveys' specialized software. Vectors used on the interpretation maps were also converted to GeoTIFFs using Fugro Airborne Surveys' specialized software.\n2011\n\n\nMap overlays - Fugro staff obtained the Alaska PLSS Section Grid (1995) from the State of Alaska, Department of Natural Resources, Division, Land Records Information Section (LRIS) website. The section grid file was built by Alaska DNR from original protraction diagram data. It was used as a starting point for the section grid digital file included in GPR 2011-2. The original file was in NAD27 datum, but currently is on the web in WGS 84. The section grid is used on the maps without topography and is provided in digital format in this publication. The publication date given above reflects the current metadata file for the Alaska PLSS Section Grid.\n2011\n\n\nPrint files - The HPGL/2 files were created with HP Designjet 5000 printer driver v5.32 and plot on some plotters, but not all plotters correctly. The Adobe Acrobat format files were created with Adobe Acrobat Distiller v9.0 from Postscript files.\n2011\n\n\n\n\n\n\n\nUniversal Transverse Mercator\n\n4\n\n0.999600\n-159\n0\n500000.000000\n0\n\n\n\n\ncoordinate pair\n\n.01\n.01\n\nMeters\n\n\n\nNorth American Datum of 1927\nClarke 1866\n6378206.4\n294.9786982\n\n\n\n\n\n\ngeotiffs\nImages on the interpretation maps and the EM anomaly map are provided as separate GeoTiff files.\nFugro Airborne Surveys\ngeotiffs\n\n\n\n\nmaps_hpgl2\nhpgl2 format (.prn) maps. See gpr2011_004_readme.pdf.\nFugro Airborne Surveys\nmaps_hpgl2\n\n\n\n\nmaps_pdf\nAdobe Acrobat (pdf) format maps. See gpr2011_004_readme.pdf.\nFugro Airborne Surveys\nmaps_pdf\n\n\n\n\nproject_report_em_anomalies\nAdobe Acrobat format of Fugro Airborne Surveys' project report with interpretation EM anomaly picks for the report in csv and Geosoft ASCII XYZ formats. File 'gpr2011-4_emanom_readme.pdf' included.\nFugro Airborne Surveys\nproject_report_em_anomalies\n\n\n\n\nsm_profiles\nAdobe Acrobat format of Fugro Airborne Surveys' project stacked-multi channel profile. See Project Report for more information.\nFugro Airborne Surveys\nsm_profiles\n\n\n\n\nvectors\nESRI Shape and Autocad DXF of interpretation, EM anomalies, and various locational reference files. See gpr2011_004_readme.pdf.\nFugro Airborne Surveys\nvectors\n\n\n\n\n\n\n\nAlaska Division of Geological & Geophysical Surveys\n\n\nmailing and physical\n
3354 College Road
\nFairbanks\nAK\n99709-3707\nUSA\n\n(907)451-5020\n(907)451-5050\ndggspubs@alaska.gov\n8 am to 4:30 pm, Monday through Friday, except State holidays\nPlease 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.\n\n\nGPR 2011-4\nThe 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.\n\nCurrent geophysics publications are available on paper or Mylar. Please ask for the maps to be printed from HPGL/2 files to ensure the best quality image. To purchase printed reports and maps, contact DGGS by phone (907-451-5020), e-mail (dggspubs@alaska.gov), or fax (907-451-5050). Payment accepted: cash, check, money order, VISA, or MasterCard.\nContact DGGS for current pricing\n\n\n\n\nDGGS geophysics datasets are typically compilations of multiple digital data file formats. These formats may include: GeoTiff, ESRI shapefile, Geosoft binary grid (GRD), Microsoft Office documents, PDF, ER Mapper ERS, ASCII text files (including CSV), Geosoft ASCII grid (GXF), Geosoft database, AutoCAD DXF, Geosoft plot file (PLT), Printer files (HPP, PRN, or other), digital images (multiple formats), digital video (multiple formats), Geosoft ASCII XYZ, Geosoft ASCII files (PLY, i0, EXP), and KMZ\n\n\n\n\n\nhttp://dx.doi.org/10.14509/27081\n\n\n\n\n\nDigital files on DVD are available for $10 plus shipping and are free when downloaded online.\n\nRequisite software varies according to the file format. Possible software requirements include, but are not limited to: Geosoft Oasis montaj (full version and viewer), INTREPID geophysical software, ESRI Arc GIS products, MapInfo, Global Mapper, UltraEdit, NotePad ++, Microsoft Office or open source office software, Adobe Reader, Lerup PrintFile, Google Earth, ER Mapper\n\n\n20150512\n\n\n\nAlaska Division of Geological & Geophysical Surveys\n\nMetadata Manager\n\nmailing and physical\n
3354 College Road
\nFairbanks\nAK\n99709-3707\nUSA\n\n(907)451-5020\n\n\nFGDC Content Standard for Digital Geospatial Metadata\nFGDC-STD-001-1998\nIf the user has modified the data in any way they are obligated to describe the types of modifications they have performed in the supporting metadata file. User specifically agrees not to imply that changes they made were approved by the Alaska Department of Natural Resources or Division of Geological & Geophysical Surveys.\n\nhttp://www.dggs.alaska.gov/metadata/dggs.ext\ndggs metadata extensions\n\n\n\n","source_transform":null,"status":"error"}