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EMAG2: Earth Magnetic Anomaly Grid (2-arc-minute resolution)

Published by NOAA National Centers for Environmental Information | National Oceanic and Atmospheric Administration, Department of Commerce | Catalog Last Checked: May 06, 2026 at 04:13 PM | Dataset Last Updated: August 07, 2009 at 12:00 AM
EMAG2 is a global Earth Magnetic Anomaly Grid compiled from satellite, ship, and airborne magnetic measurements. It is a significant update of our previous candidate grid for the World Digital Magnetic Anomaly Map. The resolution has been improved from 3 arc-minutes to 2 arc-minutes, and the altitude has been reduced from 5 km to 4 km above the geoid. Additional grid and track line data have been included, both over land and the oceans. Wherever available, the original shipborne and airborne data were used instead of precompiled oceanic magnetic grids. Interpolation between sparse track lines in the oceans was improved by directional gridding and extrapolation, based on oceanic crustal age model. The longest wavelengths (>330 km) were replaced with the latests CHAMP satellite magnetic field model MF6.

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Complete Metadata
@type dcat:Dataset
accessLevel non-public
contactPoint 
                                            {
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  "hasEmail": "mailto:datagovsupport@gsa.gov"
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describedByType application/octet-steam
description EMAG2 is a global Earth Magnetic Anomaly Grid compiled from satellite, ship, and airborne magnetic measurements. It is a significant update of our previous candidate grid for the World Digital Magnetic Anomaly Map. The resolution has been improved from 3 arc-minutes to 2 arc-minutes, and the altitude has been reduced from 5 km to 4 km above the geoid. Additional grid and track line data have been included, both over land and the oceans. Wherever available, the original shipborne and airborne data were used instead of precompiled oceanic magnetic grids. Interpolation between sparse track lines in the oceans was improved by directional gridding and extrapolation, based on oceanic crustal age model. The longest wavelengths (>330 km) were replaced with the latests CHAMP satellite magnetic field model MF6.
distribution 
                                            [
  {
    "@type": "dcat:Distribution",
    "title": "Metadata Landing Page",
    "accessURL": "https://www.ncei.noaa.gov/metadata/geoportal/rest/metadata/item/gov.noaa.ngdc.mgg.geophysical_models:EMAG2/html",
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    "@type": "dcat:Distribution",
    "title": "EMAG2 Home Page",
    "accessURL": "http://geomag.colorado.edu/emag2-earth-magnetic-anomaly-grid-2-arc-minute-resolution.html",
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  {
    "@type": "dcat:Distribution",
    "title": "EMAG2 Full Resolution Map poster",
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    "mediaType": "application/pdf",
    "description": "PDF of Full Resolution Map of EMAG2 as a poster",
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  {
    "@type": "dcat:Distribution",
    "title": "EMAG2 Full Resolution Map poster",
    "format": "JPEG",
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    "description": "JPG of Full Resolution Map of EMAG2 as a poster.",
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    "title": "EMAG2 Full Resolution Map image",
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    "description": "JPG of Full Resolution Map of EMAG2 as an image.",
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    "describedByType": "application/octet-stream"
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    "@type": "dcat:Distribution",
    "title": "EMAG2: A 2-arc-minute resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne and marine magnetic measurements",
    "format": "PDF",
    "mediaType": "application/pdf",
    "description": "Preprint of manuscript "EMAG2: A 2-arc-minute resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne and marine magnetic measurements", submitted for publication to Geochem. Geophys. Geosyst.",
    "downloadURL": "http://geomag.colorado.edu/images/EMAG2/emag2.pdf",
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  },
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    "@type": "dcat:Distribution",
    "title": "Google Earth",
    "format": "KML",
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    "title": "XYZ/Zip",
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    "description": "EMAG2 ASCII grid of the magnetic total intensity at 4km above WGS84 ellipsoid.",
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    "title": "GIS TIFF",
    "format": "TIFF",
    "mediaType": "image/tiff",
    "description": "A georeferenced TIFF (GeoTIFF) with a resolution of 2-arc-minutes, which can be opened by ESRI ArcGIS or any other GIS application. The values (nT) are stored as 32-bit floating point.",
    "downloadURL": "http://geomag.colorado.edu/images/EMAG2/EMAG2_V2.tif",
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    "title": "GMT Grid",
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    "description": "A GMT (Generic Mapping Tools) compatible netCDF grid with resolution of 2-arc-minutes. The values (nT) are stored as 32-bit floating point.",
    "downloadURL": "http://geomag.colorado.edu/images/EMAG2/EMAG2_V2.grd",
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    "title": "Color-relief",
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    "description": "A 24-bit RGB georeferenced TIFF (GeoTIFF) color-relief visualization of the EMAG2 grid, which can be opened by ArcGIS or any other GIS application.",
    "downloadURL": "http://geomag.colorado.edu/images/EMAG2/EMAG2_image_V2.tif",
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    "description": "EMAG2 (Version 2.0) ASCII grid of the magnetic total intensity at 4km above WGS84 ellipsoid. This version was produced without directional gridding. Therefore, it has much sparser coverage but reflects more closely the actual measurements.",
    "downloadURL": "http://geomag.colorado.edu/images/EMAG2/EMAG2_no_directional_gridding_2009-01-06.xyz.gz",
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    "description": "Global Change Master Directory (GCMD). 2024. GCMD Keywords, Version 19. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords",
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identifier https://data.noaa.gov/waf/NOAA/NESDIS/NGDC/MGG/Geophysical_Models/iso/xml/EMAG2.xml
issued 2009-08-07T00:00:00.000+00:00
keyword 
                                            [
  "Earth Science > Solid Earth > Geomagnetism > Magnetic Field",
  "Earth Science > Solid Earth > Geomagnetism > Magnetic Intensity",
  "Earth Science > Solid Earth > Geomagnetism > Magnetic Anomalies",
  "Geographic Region > Global",
  "DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce",
  "DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce"
]
language 
                                            []
license https://creativecommons.org/publicdomain/zero/1.0/
modified 2009-08-07T00:00:00.000+00:00
publisher 
                                            {
  "name": "NOAA National Centers for Environmental Information",
  "@type": "org:Organization"
}
rights otherRestrictions
spatial 180.0,-90.0,-180.0,90.0
temporal 1946-01-01T00:00:00+00:00/2008-12-01T00:00:00+00:00
title EMAG2: Earth Magnetic Anomaly Grid (2-arc-minute resolution)

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