The Ordnance Survey has announced that the triple alignment of true north, grid north (on OS maps) and magnetic north—the so-called three norths—has left England and is now over the North Sea. It’ll make landfall again in Scotland late next year. This is an artifact of, and specific to, Ordnance Survey maps, whose grid has a meridian is two degrees west longitude, east and west of which there is some difference between true north and grid north, and the movement of the north magnetic pole. In other words, the third north is product-specific. The triple alignment has been working its way north for the past three years; see my previous post for more.