Magnetic & Grid North

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whoisthechallenger
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Magnetic & Grid North

Post by whoisthechallenger »

I'm a little confused.

Please can someone confirm that in 2014 Magnetic and grid North will align, and we'll no longer have to add numbers to a clue's bearings when plotting them on an OS map.

In 2015, the ditty 'ADD to MAG, RID to GRID' will be obsolete - but only for South West England.

Thanks.
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kk
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Post by kk »

Hmmm don't know about that I thought it was something like a decrease of 0.5* every 5 yrs?
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Post by Colin »

I think the magnetic Declination is currently running about 0° 9' or .15 Degree's east a year. The current Declination is around 2° 51' W or 2.85 Deg.

Hope this helps

Colin
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whoisthechallenger
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Post by whoisthechallenger »

I don't want to sound like an anorak now!

It didn't help much, but it did settle an argument. Unless you are comparing Magnetic and True North...
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Post by Colin »

Hi
I was referring to Magnetic and True North.

If you look at your map key it will have Grid north / Magnetic north and True north Declinations. working on the principle of a shift of 0° 9' or .15 Degree's east of Magnetic north each year Grid north and magnetic north should be the same around 2019ish

working on the same principle Magnetic and true north should be the same around 2025.


Colin
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Post by The Merry Wives of Lode »

For what it is worth, the best site I know of for finding out magnetic variation at any time is:

www.magnetic-variation.com
:lol: :roll:
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Post by Colin »

Everyone has a photographic memory. My problem is I don't have any film.

www.colin-masters.com
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Post by The Merry Wives of Lode »

You are right, I do mean www.magnetic-declination.com.

I appear to have a photographic memory but no film!!

Sorry to any one if i have misled them.

:cry: :oops:
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The Sly Fox
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Post by The Sly Fox »

The Merry Wives of Lode wrote: Sorry to any one if i have misled them.
No problem.
Oh, and welcome to the site
:D
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whoisthechallenger
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Post by whoisthechallenger »

Well this post runs and runs! Thanks for the website info Sly Fox and Merry Wives Of Lode (and welcome to the forum)! It all seems to support the Ordnance Survey explanation of Magnetic Variation (see http://www.ordnancesurvey.co.uk/oswebsi ... north.html).

Penzance and the tip of Cornwall will get Magnetic North/Grid North parity in early 2015.

However, it will take up to a further 4 years for such an effect to reach Dartmoor and our clues.
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trekkernod
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Post by trekkernod »

Hi,
Regarding the Variation between Grid, True & Magnetic North.
If you have a current issue of the Ordnance Survey Explorer Map No.28 - Dartmoor, and view the South Sheet. My map is Issue B2, not got B3 yet.
In the bottom Left Hand corner you will see the Legend details for the map. On the far Right Hand side of this information box you will see details about the variation of the North's.
On my map, as of July 2010: At the centre of the N & S sheets:
True North is 1*28' and 1*29' east of grid north respectively.
Magnetic North is estimated at 1*28' and 1*25' West of grid north respectively.
Annual change is approximately 09' east.

Hope info helps.
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whoisthechallenger
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Post by whoisthechallenger »

Its in the news, so I thought I'd comment. To quote the article: "in a small area of England west of Penzance, the grid magnetic angle is slightly to the East." For navigation poets out there: 'Grid to mag - get rid. Mag to grid - add.' And that doesn't sound so catchy!

http://www.grough.co.uk/magazine/2014/0 ... rth-shifts
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