Why does magnetic north vary by location?

• A. Because the Earth's magnetic field is irregular and varies spatially.
• B. Because it is fixed and identical everywhere.
• C. Because it is defined by local weather only.
• D. Because it points to the South Pole at some locations.

Answer: (A)

The direction a compass points (magnetic north) varies because the Earth’s magnetic field is not a perfect, uniform field. It’s shaped by complex, moving currents in the outer core and by irregular magnetization in the crust, which create local variations in both the strength and direction of the field. A compass aligns with the local magnetic field vector at your location, so the heading it indicates changes from place to place. This also means the angle between true north and magnetic north, called magnetic declination, differs across the globe and shifts over time as the core and crustal fields evolve. The other options don’t fit because weather doesn’t set magnetic direction, the field isn’t identical everywhere, and it doesn’t simply point to the South Pole at some locations.