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 Centers for Environmental Information 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.
The geomagnetism calculators have been transitioned to https only. Users of the
API need to make the request to the https page instead of the http page. Example request: https://www.ngdc.noaa.gov/geomag-web/calculators/calculateDeclination?lat1=40&lon1=-105.25&resultFormat=pdf
