To clarify, it was an alignment of True, Magnetic, and Grid North. It was occurring at a point that happened to occur in England and was travelling slowly North for the past few years and now exists over water.

Magnetic North is the direction a compass points in a particular location and moves with shifts in earths magnetic field as well as local anomalies.

True North is parallel to the axis of Earths rotation and moves as earth wobbles and sways like a slightly unbalanced spinning top.

Grid North is perpendicular to lines of Longitude which is "fixed" to a given geographic reference frame. For the UK that would be OGSB36, GPS uses WGS84, other countries may adopt different systems.

All this means that an alignment of all 3 norths can occur at multiple places on earth or none at all.