Declination
Definition and meaning of Declination in real estate.
Declination is the angular difference between magnetic north and geographic, or true, north at a specific location on the earth. In property surveying, measuring and correcting for this difference is essential for establishing accurate boundary lines.
In more detail
Surveyors historically used magnetic compasses to establish property lines, but because the earth's magnetic poles drift over time, magnetic readings change. True north remains constant, so surveyors must calculate and apply a declination correction to align magnetic survey lines with geographic coordinates. This correction is measured in degrees east or west of true north.
If a surveyor fails to adjust for declination, the property boundaries on a map will not match the physical coordinates on the ground. Modern surveys typically use global positioning system technology, which bypasses magnetic declination issues.
Key facts
| Category | Legal, Titles & Closing |
|---|---|
| Applies to | Land surveying, property boundary mapping, and legal description drafting |
| Cause of variation | Drift of the earth's magnetic fields over time and geographic location |
| Modern resolution | Use of global positioning system tools to establish absolute geographic coordinates |
A surveyor reviewing a historical deed from the early twentieth century applies a declination correction of several degrees to correctly locate the property's boundary markers on a modern map.
Frequently asked questions
Why does declination matter in real estate transactions?
Accurate declination adjustments ensure property boundary descriptions in deeds match the actual land area, preventing property line disputes between neighbors.
Does declination stay the same over time?
No, declination changes constantly because the location of the earth's magnetic north pole drifts, requiring surveyors to check updated declination models.