The convergence will take place for the first time in the south of the UK. So it will probably take about three and a half years to get back north. A convergence that has never happened before. From the memory of a scientist. That of the three northerners …
Investigation of the ordinance, the UK’s government mapping agency, has just announced it. An event is about to occur in the country in early November 2022. The alignment on the flank of a southern UK town – the coastal village of Langton Matravers – of the three northerners: true north, magnetic north and map north.
Yes. Because there are actually three definitions of the north. The direction of true north, that of geographic north, is that of the line of longitude that joins the North Pole. She doesn’t move. The direction of magnetic north is the direction that connects a point on Earth to the point where our planet’s magnetic field points downward. This is roughly the direction the compasses indicate. And it varies slightly over time. According to the variations of the magnetic field of our planet. Finally, the north direction on the maps is simply given by the lines drawn on the maps. The difference with the true north derives from the need to overcome the curvature of the Earth.
Three and a half years to go north
According to experts fromInvestigation of the ordinance, it is essentially the movement of magnetic north that allows the three nords to converge. So predictions may still evolve based on updates of Earth’s magnetic field observations by the British geological survey (BG). But at the moment, specialists predict that after being made in Langton Matravers, the triple alignment will move north by Christmas, passing through Birmingham and reaching Yorkshire in August 2024. In August 2025 it will leave the English coast via Berwick-Upon -Tweed before returning in May 2026 south of Newburgh in Scotland. In July 2026 he will make his last stop in Fraserburgh.
“It is no exaggeration to say that this is an event that has never happened before. Magnetic north moves slowly, so it will likely be several hundred years before this alignment repeats itself. “says Mark Greaves, Earth measurement expert at Investigation of the ordinancein a press release. “It is an unrepeatable event. Due to the unpredictability of the magnetic field over long time scales, it is not possible to say when it will recur. “adds Susan Macmillan, a BGS doctor. An interesting oddity, but without consequences for those who use maps and compasses. The same rules will continue to apply for them.