The position of `` north '' pointed by the N pole of the compass has moved 2250 km in 190 years
Generally speaking, `` north '' refers to the North Pole , which is the northernmost point of the Earth's rotation axis, but the `` North '' indicated by the N pole of the compass needle is not the North Pole, but the Earth's magnetic field ( geomagnetic ) It is magnetic north determined by. The position of `` north '' pointed to by this compass has moved about 2250 km in about 190 years, and the United States Oceanic and Atmospheric Administration (NOAA) updated the World Magnetic Model (WMM) on December 10, 2019 to correct magnetic north misalignment Did.
World Magnetic Model 2020 Released | News | National Centers for Environmental Information (NCEI)
Earth's Magnetic North Pole Keeps Moving Towards Siberia at a Mysteriously Fast Pace
The Earth's magnetic field is said to have existed for about 4 billion years ago, and it fluctuates mainly due to the movement of the Earth's crust and mantle , so the position of magnetic north is constantly moving. NOAA has pointed out that magnetic north has moved as much as 2250 km in about 190 years since the exact location of magnetic north was discovered in 1831.
NOAA says, “The movement of magnetic north is generally very slow, so scientists can track its position fairly easily.” However, the movement of magnetic north has been changing rapidly in the 20 years since 1990. The average speed of magnetic north movement over the past 20 years is 55 km per year, and it seems that it is moving in the direction of Siberia as seen from the North Pole.
According to the latest data, the speed of magnetic north moving toward Siberia is 40km / year, which is slowing down slightly, but it is still faster than the past few hundred years. Ciaran Beggan , a researcher at the British Geological Survey , pointed out, “The movement of magnetic north since 1990 is much faster than that of the past four centuries.” However, the exact mechanism by which magnetic north moves is still unclear.
Magnetic north is constantly moving, but researchers are constantly observing the earth's magnetic field to build a world magnetic model (WMM). WMM is used by the United States National Aeronautics and Space Administration (NASA) , Federal Aviation Administration (FAA) , military, etc., as well as GPS and other navigation systems, map services, and compass apps. It can cause problems in more than one area. So researchers track the Earth's magnetic field and the position of magnetic north, and regularly update WMM.
On December 10, 2019, NOAA's National Centers for Environmental Information , which manages WMM, and the British Geological Survey released the latest version of WMM. As a result, the system using WMM can detect the position of magnetic north quite accurately at the time of article creation, and consumers can know the accurate position with various applications and services.
WMM is scheduled to be released every 5 years, and this release is scheduled to be used until 2025. However, if there is a sudden change in the magnetic field, unintended modifications may be introduced. For example, in February 2019, an unscheduled WMM correction was made because the movement of magnetic north was faster than expected.
The Arctic magnetic field moves suddenly and an unexpected magnetic model correction is done-GIGAZINE
in Science, Posted by log1h_ik