Context: News publications across the world have been reporting that the magnetic north pole is drifting fast from the Canadian Arctic and towards Russia.
What is Magnetic North Pole? How is it different from Geographic North Pole?
The Earth has two north poles- magnetic and geographic.
- Geographic north pole- It is northern axis around which the earth rotates and is fixed. The North Pole is located in the middle of the Arctic Ocean.
- The Magnetic North Pole (also known as the North Dip Pole) is a point on Ellesmere Island in Northern Canada where the northern lines of attraction enter the Earth.
A compass needle will point to the Magnetic North Pole – which is different from the geographic north.
Origin of Earth’s magnetism:
The origin of Earth’s magnetism lies in its outer core, a more than 2,000-km layer of liquid iron and some other metals like nickel, that surrounds the central core, or the innermost part. This liquid iron is in constant motion due to Earth’s rotation and various other reasons, and this motion produces a magnetic field.
What’s the issue now?
Currently, the magnetic north pole is located somewhere over northern Canada, a fact discovered in 1831 by Sir James Clark Ross. Since then the magnetic north pole has been moving across the Canadian Arctic towards Russia, and has moved hundreds of miles over the last several decades. This phenomenon is known as the Polar Shift Theory.
Scientists have now realised the pace of this movement has suddenly increased, quite significantly, from about 14-15 km per year till the 1990s to about 55 km per year in the last few years. This has led to scientists updating the World Magnetic Model (WMM) that tracks this movement. It was a year ahead of schedule.
Why it is moving faster?
Scientists do not have full clarity on. The movement of liquid iron and other metals in the outer core of the Earth is known to influence the magnetic field, but this movement is chaotic and turbulent. Scientists do not fully understand how the movement happens or why.
The study of the phenomena happening inside the earth can only be done indirectly or through computer modelling, because of the extremely hot temperatures prevailing there. Scientists hope that this acceleration in the shifting of magnetic north pole would throw some new insights into the phenomena happening deep inside the Earth’s surface.
The consequences:
The entire transportation sector, especially aviation and shipping, depends on correctly knowing the position of magnetic north to chart out their navigation paths. Similarly, it is crucial for militaries, who need to know this for firing their missiles or for other purposes. Knowing the magnetic north is vital for a number of civilian applications as well.
The compasses that are used in modern instrumentation are much more sophisticated, digital and more accurate. This is the reason why they need to be recalibrated to reflect the change in the magnetic north pole. This is what the unscheduled release of the WMM has done.
What is the World Magnetic Model?
James Clark Ross first located magnetic north in 1831 in the scattered islands of Canada’s Nunavut territory. Since then, the pole has largely marched north, traversing hundreds of miles over the last several decades.
- To keep up with all these changes, the U.S. National Oceanic and Atmospheric Administration and the British Geological Survey developed what eventually became known as the World Magnetic Model.
- The model is updated every five years, with the last update in 2015. Between each update, scientists check the model’s accuracy against data from ground magnetic observatories and the European Space Agency’s Swarm mission—a trio of magnetic-field mapping satellites that zip around Earth 15 to 16 times each day.
Sources: Indian Express.
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