GeoMapSuite
Geodesy & Datums

Magnetic Declination (Magnetic Variation)

Direct Definition: Magnetic declination is the angle between magnetic North (the direction the north end of a compass needle points) and true geographic North.

Technical Details & Mathematical Formulation

Magnetic declination varies continuously by geographic location and drifts over time as Earth molten iron core dynamic magnetic field fluctuates. The World Magnetic Model (WMM) is updated every 5 years by NOAA and the British Geological Survey.

Mathematical Formula:\text{True Bearing} = \text{Magnetic Bearing} + \text{Declination}
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Related Geodetic Concepts

Frequently Asked Questions

People Also Ask About Magnetic Declination (Magnetic Variation)

Answers to key questions, technical definitions, and practical geodetic applications.

QWhat does the term "Magnetic Declination (Magnetic Variation)" mean?

Magnetic declination is the angle between magnetic North (the direction the north end of a compass needle points) and true geographic North.

QWhat is the mathematical or technical basis of Magnetic Declination (Magnetic Variation)?

Magnetic declination varies continuously by geographic location and drifts over time as Earth molten iron core dynamic magnetic field fluctuates. The World Magnetic Model (WMM) is updated every 5 years by NOAA and the British Geological Survey.

QHow do professionals use Magnetic Declination (Magnetic Variation) in GIS and surveying?

Cartographers, geospatial software engineers, and navigators utilize Magnetic Declination (Magnetic Variation) to guarantee mathematical precision and consistent spatial reference frames across global datasets.

QWhich category of geodesy does Magnetic Declination (Magnetic Variation) belong to?

This concept is cataloged under the "Geodesy & Datums" domain in the GeoMap Suite cartographic knowledge index.

QCan I test or calculate Magnetic Declination (Magnetic Variation) on GeoMap Suite?

Yes. You can test live coordinates and see practical examples using our companion Bearing Calculator tool.

QWhat are key concepts related to Magnetic Declination (Magnetic Variation)?

Directly related terms include Azimuth & Bearing, WGS84 Datum.