Description
EMAG2v3 is a global Earth Magnetic Anomaly Grid compiled from satellite, ship, and airborne magnetic measurements. It is a significant update of the previous release of the Earth Magnetic Anomaly Grid. The resolution remains 2 arc-minutes, and the altitude of 4 km above the geoid is still supported, but an additional product, a grid that is observed at sea-level over oceanic regions, has been produced. New additions 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 using a kriging algorithm, which specializes in heterogeneous data distribution gridding, in order to create a compilation as true to the observed data as possible, and avoid using a priori information. The longest wavelengths (>300 km) were replaced with the latests satellite lithosphere magnetic field model, MF7.
Resources
| Name | Format | Description | Link |
|---|---|---|---|
| Derivation and Error Analysis of the Earth Magnetic Anomaly Grid at 2 Arc-Minute Resolution Version 3 (EMAG2v3) | Unknown | A science paper about the construction and evaluation of the Earth Magnetic Anomaly Grid 2 Arc-Minute Resolution Version 3 | Open resource |
| GCMD Keyword Forum Page | Unknown | 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 | Open resource |
| GCMD Keyword Forum Page | Unknown | 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 | Open resource |
| GCMD Keyword Forum Page | Unknown | 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 | Open resource |
| NCEI Contact Information | Unknown | Information for contacts at NCEI. | Open resource |
| Metadata Landing Page | Unknown | Open resource | |
| EMAG2v3 Format Description | Text | ASCII text file that contains format description of the EMAG2v3 CSV data file. | Open resource |
| Map of Source Grid Codes | PNG | PNG of EMAG2v3 codes to designate which grid is primarily responsible for the anomaly value for each cell. | Open resource |
| Map of Estimated Error Values | PNG | PNG of EMAG2v3 estimates of the error in nanoTesla for each cell. | Open resource |
| EMAG2v3 Full Resolution Map of Sea Level Anomalies | PNG | PNG of EMAG2v3 as a poster at sea level over oceanic regions. | Open resource |
| Sea Level GIS TIFF | TIFF | A georeferenced TIFF (GeoTIFF) for EMAG2v3, where the altitude is at sea level over oceanic regions, 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. | Open resource |
| Upward Continued Google Earth Image | KML | KMZ plugin for Google Earth of EMAG2v3 as a poster at a consistent 4km altitude with data gaps filled with MF7 values. Requires installation of Google Earth. | Open resource |
| EMAG2v3 Full Resolution Map of Upward Continued Anomalies | PNG | PNG of EMAG2v3 as a poster at a consistent 4km altitude. | Open resource |
| Upward Continued GIS TIFF | TIFF | A georeferenced TIFF (GeoTIFF) for EMAG2v3, where the altitude is at a consistent 4km altitude, 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. | Open resource |
| EMAG2v3 ASCII CSV data file | ZIP | Zip file containing the comma delimited ASCII grid that contains i and j grid indicies, latitude and longitude cell centered location information, magnetic anomalies at a consistent 4km elevation, sea level over oceanic regions, anomaly source grid code, and an error estimate for each cell. | Open resource |
| Home Page | HTML | emag2.html | Open resource |