Tag

grid north

21
Mar
2019
7

Magnetic north continues its march to the east

As expert map readers will know, when you’re out and about navigating with a compass, there is a difference between magnetic north (where the compass points) and grid north (the vertical blue grid lines shown on OS maps). And if you’re exploring in the west of Great Britain, there is a change to be aware of…

The difference between magnetic north and grid north is often referred to as grid magnetic angle and it not only varies from place to place, but changes with time too, and needs to be taken into account when navigating with a map and compass.

In 2014 there was a significant event in the changing direction of magnetic north relative to grid north on OS maps. For the first time in Great Britain since the 1660s, magnetic north moved from being to the west of grid north to the east. The change started in the very south west corner of Britain, currently affects the areas to the west of the line on our map, and will slowly progress across the whole country over the next 12 to 13 years.

Map of Great Britain with a line marking the areas now to the east of magnetic north for the first time since the 1660s

The line represents the approximate path of where magnetic north currently equals grid north

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