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 NOAA > NESDIS > NGDC > MGGD & STP > Geomagnetism

EMAG2, background image © GFZ Potsdan 1999

What's New?

new CIRES geomagnetism page
new Enhanced Magnetic Model 2015!
new High Def Geomagnetic Model (HDGM2015)!

Models are joint research with:

The Cooperative Institute for Research in Environmental Sciences (CIRES).


The study of geomagnetism is one of the oldest of the geophysical sciences. The geomagnetic fields have been observed and used from ancient times. Modern uses of geomagnetic data include navigation and mineral exploration. The National Geophysical Data Center develops and distributes models of the geomagnetic field and maintains archives of geomagnetic data to further the understanding of Earth magnetism and the Sun-Earth environment.

Online Calculators
Declination Grid Calculation Magnetic Field US Historic Declination
NOAA has updated the magnetic calculator(s). The older style calculators will continue to be available for some time through the CIRES Geomagnetism research site. Follow the following off-site link for access to the backup calculators.

Geomagnetic Models &Software
newEnhanced Magnetic Model (EMM)  Intl Geomagnetic Reference Field (IGRF)
 World Magnetic Model (WMM) Maps and Images (ftp)
new High Definition Geomagnetic Model (HDGM) new Historic Declination Mapviewer 

Geomagnetic Data
Airborne Observatory
Indices Paleomagnetic
Marine Magnetic Space Physics Interactive Data Resource

Trackline (marine and airborne) data and derived geomagnetic models and software are managed by NGDC's Marine Geology & Geophysics Division (MGGD) and collocated World Data Center for Geophysics and Marine Geology.

map and north arrow
Declination Calculator

World Magnetic Model (WMM) declination
World Magnetic Model

Enhanced Magnetic Model (EMM)
newEnhanced Magnetic Model