Airports Renumber Runways Worldwide as Magnetic North Pole Drifts 36 Kilometers a Year
Updated
Updated · spacedaily.com · Aug 6
Airports Renumber Runways Worldwide as Magnetic North Pole Drifts 36 Kilometers a Year
1 articles · Updated · spacedaily.com · Aug 6
Summary
Runway numbers at airports worldwide are being repainted and signs replaced when magnetic bearings shift by about 3 to 4 degrees, making existing designators inaccurate for pilots.
Those two-digit labels reflect a runway’s magnetic heading rounded to the nearest 10 degrees, so movement of the magnetic north pole changes the correct number even when the pavement itself never moves.
NOAA and the British Geological Survey said the pole, generated by shifting flows in Earth’s molten outer core, drifted about 36 kilometers over the past year after peaking near 55 kilometers annually in the early 2000s.
That faster drift already forced the first unscheduled World Magnetic Model update in 2019, and airports from Tampa and Fairbanks to Geneva, Reno and London Stansted have periodically shut runways to renumber them.