The magnetic north pole migration - What a Pilot should know

by Marine-Pilots.com - published on 22 February 2019

Since the turn of the millennium 55 km per year

The Arctic magnetic pole does not move anymore. It runs, faster and faster. In recent years, even faster than expected. Therefore, geo-researchers have now had an unscheduled change to their world model and adjust their calculations, so that navigation with compass and other navigation aids such as a Pilot Plug, used by pilots around the world, continue to work.


Regular compass corrections are important

A compass has to be calibrated regularly, because the magnetic field of our Earth, on which the compass is oriented, constantly changes slightly and deviates from place to place. The corrections are especially important for captains and pilots in high latitudes. Elsewhere it does not matter so much when the compass is pointing not exactly to the north, to the point around which the earth revolves, but to the magnetic pole nearby. Ships and aircraft in the Arctic are particularly dependent on the most accurate navigational data possible.


Unscheduled publication of compass corrections

The Arctic magnetic pole, for example, is located near the geographic North Pole, and it changes its position noticeably every year. For this reason, experts must constantly adapt the model used for compass correction. Now, however, the World Magnetic Model has been temporarily revised. It is being produced by the National Geophysical Data Center (NGDC) in the USA in cooperation with the British Geological Survey (BGS) in the United Kingdom.


Official corrections so far are in a five-year cycle

Normally, the magnetic model of the Earth is revised every five years. The latest version is from 2015, so a new release of the data would have been necessary by the end of this year. But because the pole is moving so fast, the researchers found themselves forced to act faster.


By the end of 2019, there will be the next revision on the regular schedule.

Since the first positioning in 1831, the Arctic magnetic pole has already moved by 2300 kilometers - and it continues to move. Since the turn of the millennium, the speed has been around 55 kilometers per year. It is traveling from the area of the Canadian Arctic Islands across the central area of the Arctic Ocean towards Siberia.


The liquid earth core allows the magnetic pole to migrate

The reason for the migration of the magnetic North Pole lies in the interior of the earth. There, movements in the liquid part of the earth's core cause the magnetic field to form, and researchers speak of the so-called geodynamo. And these movements of molten iron and nickel vary minimally over time - causing the pole to migrate.


The next pole reversal will come

The polarity of the field has been reversed repeatedly in the past, which can be demonstrated by rock samples. Currently, its strength is weakening, which could be an indication of a so-called pole reversal. On geological scales, this event is overdue, so to speak, the last time it occurred was 780,000 years ago. The question is not whether, but when the next pole reversal will take place.


Frank Diegel, TRENZ GmbH, Germany
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