skip navigation menu
On the Isogonic Lines Cover the East-Siberia and Japan (1)
(1) Isogonic lines in the age of 1600 and 1700 over Japan Island are obtained using most reliable data observed by ships along the coast of Japan in that ages.
(2) Over the south polar region, the total intensity maximum position is found close to the south magnetic pole, and the isogonic lines of this region distribute regularly. On the other side, over the north polar area, the north magnetic pole (N・P) and the total intensity maximum place (M・P) are located opposite to the geographical north pole. Such distribution of the above special magnetic positions results the oval shape isomagnetic lines over the east Siberia and Japan.
As the magnetic intensity of M・P increases relative to that of N・P, the declination of this region tends to westward, and the center of oval moves northward along nearly 130°east meridian. On the contrary, as the intensity of M・P become weaker than that of N・P, then east declinations revail over this region, following the center of oval to move southward, also along 130°east meridian.
Copyright (c) 2014 Kakioka Magnetic Observatory, Japan Meteorological Agency. All Rights Reserved.