An imaginary range in the planet's surface connecting points where magnetic declination is zero.
A line on a chart or chart joining points of zero magnetized declination.
an imaginary range connecting things on the Earth's surface where the magnetized declination is zero
an imaginary line in the earth's area moving through those places where magnetized needle points towards real north; the distinct no magnetized variation. Discover one such line into the Western hemisphere, and another in the Eastern hemisphere.