magnetic variation
True-magnetic north difference
Magnetic variation is the angle between true north and magnetic north at any given location on Earth.
Compasses point to magnetic north, which differs from geographic north, so navigators must account for this discrepancy: The chart showed a magnetic variation of 12 degrees west.
Also called magnetic declination.
The variation changes depending on where you are and shifts gradually over time.
Device showing cardinal directions
- bearingPosture or orientation
- true northDirection to the pole
- correctionFixing of mistakes
- adjustmentAlteration to improve fit
deviation · dead reckoning · piloting · seamanship · nautical chart · course plotting · waypoint · GPS
Angular distance from equator
- calibrationAdjusting for measurement accuracy
- errorFault in communication
- offsetCompensate by opposing force
- discrepancyDifference between expected and actual
drift · miscalibration · inaccuracy · inclination · flux · isogonal · epoch · survey data
Angular distance from equator
- geomagnetismEarth's magnetic field
- dipoleSeparated opposite charges
- paleomagnetismRemnant magnetism in rocks
- ionosphereCharged upper atmospheric layer
Pole-to-pole great circle
- mappingDiagram of correspondences
- surveyingMeasuring and charting terrain
- geodesyEarth measurement science
- chartingRecording data visually
topographic map · grid north · true north · UTM · map reading · orienteering · contour · projection
compass
Device showing cardinal directions
- bearingPosture or orientation
- true northDirection to the pole
- correctionFixing of mistakes
adjustment · deviation · dead reckoning · piloting · seamanship · nautical chart · course plotting · waypoint · GPS · gyrocompass
declination
Angular distance from equator
- calibrationAdjusting for measurement accuracy
- errorFault in communication
- offsetCompensate by opposing force
discrepancy · drift · miscalibration · inaccuracy · inclination · flux · isogonal · epoch · survey data
declination
Angular distance from equator
- geomagnetismEarth's magnetic field
- dipoleSeparated opposite charges
- paleomagnetismRemnant magnetism in rocks
meridian
Pole-to-pole great circle
- mappingDiagram of correspondences
- surveyingMeasuring and charting terrain
- geodesyEarth measurement science
charting · topographic map · grid north · true north · UTM · map reading · orienteering · contour · projection · datum
- navigation termsnautical charts, GPS, north, road signs, maps
- compassescompass needle, compass rose, compass card, compass heading, north
- aviation navigationDME, waypoint, radio beacon, localizer, glide slope
- compass errorsdeviation, declination
- navigationcompass, compass rose, signs, charts, navbar
- nautical chartsnautical chart, nautical charts, sea chart, marine charts, sea charts
variation, magnetic, magnetism, variations, magnetize, magnetized, magnetizing, magnetic field, electromagnetic