地磁赤道

[ noun ]
an imaginary line paralleling the equator where a magnetic needle has no dip
<noun.location>

Equator \E*qua"tor\, n. [L. aequator one who equalizes: cf. F.
['e]quateur equator. See {Equate}.]
1. (Geog.) The imaginary great circle on the earth's surface,
everywhere equally distant from the two poles, and
dividing the earth's surface into two hemispheres.

2. (Astron.) The great circle of the celestial sphere,
coincident with the plane of the earth's equator; -- so
called because when the sun is in it, the days and nights
are of equal length; hence called also the {equinoctial},
and on maps, globes, etc., the {equinoctial line}.

{Equator of the sun} or {Equator of a planet} (Astron.), the
great circle whose plane passes through through the center
of the body, and is perpendicular to its axis of
revolution.

{Magnetic equator}. See {Aclinic}.

magnetic equator \magnetic equator\ n.
An imaginary line paralleling the equator where a magnetic
needle has no dip, the dipping needle being horizontal;
called also {aclinic line}.
[WordNet 1.5]