Quinn et al. This article provides the algorithm for computing the values of the reference field from the IGRF model and secular variation values. Spatial and attribute information. The resulting data set was converted to shapefile format. Lines of constant total magnetic field intensity.
Magnetic intensity is the strength of the magnetic field.
The representation of the entity in the data. Internal sequence number of the left polygon. The length of the line in coverage units. Isovalue of the total magnetic field intensity. This value is a measure of the total strength of the magnetic field.