Military and civilian navigation are affected. On 15 January, scientists were set to update the World Magnetic Model, which describes the planet’s magnetic field and underlies all modern navigation, including Google Maps on smartphones. The previous model of the magnetic field was released in 2015 and updates have been slated for 5-year intervals. But a change is needed now. The partial federal government shutdown will delay the release of this model from January 15 until at least January 30, despite the U.S. military’s request for the update ahead of schedule.
The World Magnetic Model
This update doesn’t affect GPS receivers, which don’t rely on the magnetic north pole. A receiver instead picks up signals from multiple satellites for which the exact position in orbit is known, and use trilateration (the intersection of their signals) to determine a location. The magnetic north pole never been for longtime a fixed point. The Earth’s liquid core contributes most towards the planet’s magnetic field. It accelerated its movement over the last 40 years from movements recorded in early decades.