Thanks to a shifting magnetic north pole, Tampa International Airport must change its runway designations.

Designations indicate the compass headings of the runway, approaching from either direction. Tampa’s two parallel runways have been 18/36 (for headings of 180 degrees and 360 degrees) right and left, with a third runway designated 9/27 (for headings of 90 degrees and 270 degrees).

The airport said the designations would change to 19/1 for the parallel runways and 10/28 for the third runway effective Jan. 13.

According to The Tampa Tribune, the culprit is the magnetic north pole, which is moving nearly 40 miles a year toward Russia because of magnetic changes in the core of the planet.