What is the term for the difference in degrees between magnetic north and true north?

The term for the difference in degrees between magnetic north and true north is known as magnetic declination. This is an essential concept in navigation and surveying, as it accounts for the angular difference between the direction that a magnetic compass points (magnetic north) and the geographic north pole (true north).

Understanding magnetic declination is crucial for accurate navigation and mapping, especially when using a compass. Since magnetic declination can vary depending on your geographical location and can change over time due to shifts in the Earth's magnetic field, surveyors must be aware of the current declination value for their area to ensure the accuracy of their measurements and the orientation of their surveys.

Grid convergence, true north adjustment, and azimuth change do not specifically refer to the angle between magnetic north and true north. Grid convergence relates to the angular difference between true north and the grid north used in map projections, true north adjustment refers to making corrections based on true north rather than magnetic north, and azimuth change generally refers to shifts or movements in direction measured in degrees, but not exclusively tied to the context of magnetic and true north differences.