Fig. 7.From: Relevance of magnetic properties of soil in the magnetic observatories to geomagnetic observationThe calculated distribution of the magnetic field and its annual variation. (a) Magnetic total intensity. (b)–(d) Amplitudes of annual variations for H, D and Z components, respectively. Positive and negative signs in (b)–(d) indicate an increase and decrease, respectively, during high ground-temperature periods.Back to article page