https://www.usgs.gov/publications/magnetic-charts-united-states-epoch-1975
Approximately 24,000 measurements taken from 1900 to 1974 were analyzed by least-squares methods to produce a series of five magnetic charts of the United...
united statesfor epochmagneticcharts
https://www.usgs.gov/software/usgs-geomagnetism-programinterpolated-magnetic-perturbations-geomag-imp
Geomag-IMP is an open-source Python library for interpolating magnetic field perturbations onto geographic coordinates. Geomag-IMP provides two (for now)...
u susgsgeomagnetismmagneticperturbations
https://www.usgs.gov/publications/airborne-electromagnetic-and-magnetic-survey-data-paradox-and-san-luis-valleys
In October 2011, the U.S. Geological Survey (USGS) contracted airborne magnetic and electromagnetic surveys of the Paradox and San Luis Valleys in southern...
magnetic surveythe paradoxairborneelectromagneticdata