What term describes the angular difference between true north and magnetic north at a location?

What term describes the angular difference between true north and magnetic north at a location?

• A. Variation
• B. Deviation
• C. Compass Error
• D. True North

Answer: (A)

The angular difference between true north and magnetic north at a location is called variation. This is a property of the Earth's magnetic field at that spot and can be either east or west, meaning magnetic north lies that many degrees away from true north. You see this on nautical and aeronautical charts to convert between true bearings and magnetic bearings. Deviation, on the other hand, comes from interference within the vessel or instrument, causing the compass reading to differ from the magnetic north. Compass error is the overall discrepancy between true north and what the compass shows, combining both variation and deviation. True north is simply the geographic reference direction. So the correct term for the angular difference between true north and magnetic north is variation.

The angular difference between true north and magnetic north at a location is called variation. This is a property of the Earth's magnetic field at that spot and can be either east or west, meaning magnetic north lies that many degrees away from true north. You see this on nautical and aeronautical charts to convert between true bearings and magnetic bearings. Deviation, on the other hand, comes from interference within the vessel or instrument, causing the compass reading to differ from the magnetic north. Compass error is the overall discrepancy between true north and what the compass shows, combining both variation and deviation. True north is simply the geographic reference direction. So the correct term for the angular difference between true north and magnetic north is variation.