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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 | Metadata Last Checked: December 19, 2025 | Last Modified: 2009-08-07T00:00:00.000+00:00
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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