Attention anyone who navigates by compass, be they shipping companies, aircraft, or uber-serious hikers: North may not be where you think it is. The magnetic north, that is. Nature reports that the Earth's northern magnetic pole has moved so quickly since the last update of an official guide known as the World Magnetic Model in 2015 that scientists are jumping in early to update it again instead of waiting until 2020. The move was supposed to happen earlier this week, but it will now wait until Jan. 30 because of the government shutdown. It seems the pole, whose movement is notoriously difficult to predict, is speeding away from the Canadian Arctic on its way to Siberia much faster than scientists predicted three years ago.
The upshot is that the difference between magnetic north—where a compass needle points—and geographic, or true, north is bigger than it should be, explains Live Science. Modern navigation systems use the World Magnetic Model to help adjust for the difference between magnetic and true north. The reason for the erratic movement is unclear, but it all has to do with the complex movements of liquid iron in the core of the planet. Not helping: Scientists detected "an unusually punchy geomagnetic pulse" beneath South America in 2016, and that pulse may be a factor in the anomaly, per IFL Science. Here is how one geomagnetist explains it to Nature: "The location of the north magnetic pole appears to be governed by two large-scale patches of magnetic field, one beneath Canada and one beneath Siberia. The Siberian patch is winning." (More discoveries stories.)