n. The imaginary great circle on the earth's surface formed by the intersection of a plane passing through the earth's center perpendicular to the axis connecting the north and south magnetic poles.
geomagnetic equator
geomagnetic equator
[¦jē·ō·mag¦ned·ik i′kwād·ər] (geophysics) That terrestrial great circle which is 90° from the geomagnetic poles.