What term describes the angle between magnetic north and true north?

The term that describes the angle between magnetic north and true north is known as variation. Variation, also called magnetic declination, represents the difference in degrees between where a magnetic compass points (magnetic north) and the geographic North Pole (true north). This angle is crucial for navigation, particularly in marine and aerial contexts, where it helps navigators adjust their compass readings for accurate course plotting.

Understanding variation is essential for ensuring that navigational charts and compass readings align correctly, as discrepancies can lead to navigational errors. Measuring variation is vital for charting and land navigation, as it affects how navigators interpret compass readings based on their current location and changes in the Earth's magnetic field over time.