Lesson Open Access
De Pinho, Bruno
The earth's core behaves as a big magnet. On the surface, we measure different values in magnetic surveys as we move from one geomagnetic pole to the other. The dipole effect of the earth influences all the activities that involves magnetics on earth. This requires us to have a model to predict the earth magnetic flux based on the geographic coordinates of our magnetic surveys.
IGRF-12 means 12th Generation International Geomagnetic Reference Field and it is maintained by The International Association of Geomagnetism and Aeronomy (IAGA). From their official website:
This global main field model provides magnetic field values for any location on Earth, e.g. for navigational purposes (declination) or as a standard for core field subtraction for aeromagnetic surveys. An updated version is adopted by IAGA every 5 years.
Geologist and geophysicist basically gather magnetic data from suveys and subtract the influence of the earth's magnetic field. The result is magnetic information that is caused by the combination of the magnetic susceptibility of all the rocks in the study area.
In this article I will show you how to extract data from the IGRF-12 model using Python.