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The Arctic drift of the earth's magnetic field has crossed the primary meridian

US media said that in recent years, the north pole of the earth's magnetic field has been drifting faster than expected, and now it has crossed the primary meridian.

According to the American interesting science website reported on December 16, in the past 20 years, the geomagnetic north pole has been moving to Siberia at a speed of about 34 miles (about 55 kilometers) a year. The latest geomagnetic model released by the national environmental information center of the United States and the British Geological Survey Institute on December 10 shows that this movement process will continue, but the speed may slow down to 25 miles a year.

The geomagnetic field model can be used to calibrate the global positioning system (GPS) and other navigation measurements.

The earth's magnetic field is produced by the rotation of its iron outer core. It produces a complex but basically north-south magnetic field. For reasons not fully understood but related to the dynamics of the earth's interior, the earth's magnetic field is currently undergoing a period of weakening. This is why the geomagnetic north pole drifts.

According to the national environmental information center of the United States, as of February 2019, the geomagnetic north pole is located at 170.88 degrees east longitude and 86.54 degrees north latitude in the Arctic Ocean. Similarly, the geomagnetic south pole is not consistent with the geographical south pole; As of February 2019, the geomagnetic south pole is located at 136.02 degrees east longitude and 64.13 degrees south latitude near the coast of Antarctica.

Scientists release a new version of the 'world geomagnetic model' every five years, so the update was originally scheduled to be released in 2020. However, in February 2019, due to the rapid movement of the geomagnetic north pole, they had to release the update in advance. The 2020 model shows the 'black barrier' around the geomagnetic north pole, where the compass will become unreliable and begin to fail due to its proximity to the real North Pole. According to Newsweek, the new world geomagnetic model map also shows that the geomagnetic north pole is located to the east of the primary meridian, because the North Pole crosses this boundary in September 2019. The original meridian, also known as the Greenwich meridian, was officially defined as the longitude of zero degrees, zero minutes and zero seconds in 1884; It passes through the Royal Observatory in Greenwich, England.

It is unclear whether the geomagnetic poles will flip - that is, the north and south poles will switch - or whether the magnetic field will strengthen again in the short term. These two kinds of events have occurred in the history of the earth, but they have no significant impact on organisms. However, modern navigation systems rely on the geomagnetic north pole. As the geomagnetic poles continue to drift, they will have to be recalibrated. For example, some airports have had to rename some of their runways because they are named based on compass direction.