Geologic-geographic nerd alert

The north magnetic pole has wobbled around Canada and the Arctic very quickly for the past few years, and no one knows why. A consequence of its traversal of the Arctic has been to create an unprecedented geographic situation in the UK for the past three years, which alas is ending today:

‘True north’ is the direction to the geographic north pole; ‘grid north’ is where the vertical blue lines shown on Ordnance Survey (OS) maps converge, and ‘magnetic north’ is the direction that a compass needle points as it aligns with the Earth’s magnetic field.

In November 2022, geospatial history was made as all three ‘norths’ aligned and met at a point in Langton Matravers in Dorset, England, for the first time. Now, after three historic years together, new magnetic field data collected by the British Geological Survey (BGS) and calculations made by OS have shown that the triple alignment is set to leave England at Berwick-upon-Tweed on 13 December 2025 and move into the North Sea. It’s predicted that the triple alignment will hit land again at the end of October 2026 in Drums, just south of Newburgh in Scotland. After passing through Mintlaw, its last stop in Scotland will be Fraserburgh around mid-December 2026, before it returns to the North Sea.

The BGS concluded that "mid-December" is, in fact, today.

If you want to see how the north magnetic pole has moved for the past half-millennium, NOAA has an interactive site.

What the Ordnance Survey news article omits to mention is that true north also varies, albeit by a much smaller amount, because of small variations in the direction of the Earth's axis of rotation. The positions of the true north and south poles wander by a few metres on the Earth's surface in a mostly periodic fashion. We've known about this since the late 19th century, and it is monitored closely by the International Earth Rotation Service. Ordnance Survey grid north is fixed, of course, and coincides (as close as matters to anyone except geophysicists) with true north along the 2 degrees west meridian, which is the line along which the transverse Mercator projection of the OS grid system touches the Earth's surface.