Mal,

   Magnetic anomalies are a well known geophysical phenomena.
The earth's magnetic field periodically reverses itself.
As a rock layer with magnetic properties cools (perhaps molten magma)
it takes on the polarity of the prevailing magnetic field at that
time.
Thus the rock at a later time can either add to or subtract from the
earth's magnetic field.
Reversals in magnetic field were used to prove the plate tectonics
theory as symmetric reversals can be seen either side of the mid-ocean
ridges.

Furthermore, Scotland has well known and studies magnetic anomalies
(see references below for a start):


http://www.nature.com/nature/journal/v303/n5917/abs/303516a0.html

http://sjg.lyellcollection.org/content/24/3/215.abstract

http://www.earth.ox.ac.uk/~tony/watts/downloads/Watts71.pdf


73 Warren K2ORS
( a lapsed or should I say recovering geophysicist)




On Fri, Sep 23, 2011 at 8:55 AM, mal hamilton <[email protected]> wrote:
> Dennis
> On the motorway near Glasgow the GPS instructed me to keep right when in
> fact I had to keep to the left lane. Strange things happen in Scotland, the
> mystery was solved when I noticed the road had been altered on a couple of
> occassions, so I followed the road signs.
> It pays to keep alert and have additional nav aids.
> Now back to LF/MF observations and all quiet at present although 10 metres
> is wide open worldwide.
> de mal/g3kev
>
>
> ----- Original Message -----
> From: DENNIS EASTERLING
> To: [email protected]
> Sent: Friday, September 23, 2011 10:58 AM
> Subject: Re: LF: Re: Turbine magnets
> Hi All
>
> Chatting about this at the radio club last night, one member has noticed a
> similar effect as Mal when passing Letchworth swimming pool, though no wind
> generators in sight. Perhaps we have gremlins about?
>
> 73 Dennis M0JXM
>
> ----- Original Message -----
> From: M0FMT
> To: [email protected]
> Sent: Thursday, September 22, 2011 9:01 PM
> Subject: Re: LF: Re: Turbine magnets
> Hi all
>
> I think the MoD have a say in the locating of Wind Turbines owing to there
> effect on RADAR but nothing to do with stray magnetic fields as far as I am
> aware.
>
> 73 es GL Pete M0FMT IO91UX47VN
> From: Graham <[email protected]>
> To: [email protected]
> Sent: Thursday, 22 September 2011, 21:33
> Subject: Re: LF: Re: Turbine magnets
>
>
> I think  there  are  some problems  with  walking  in Scotland  using
> magnetic  compasses  , due to the  rocks ??
> From: Andy Talbot
> Sent: Thursday, September 22, 2011 9:15 PM
> To: [email protected]
> Subject: Re: LF: Re: Turbine magnets
> Surely if the magnetic field leaked that much, the generators would suffer
> efficiency.
> They are designed as closed magnetic circuits, with all the field lines
> closely confined in iron, with small air gaps
>
> Andy
> 'jnt
>
>
> On 22 September 2011 21:07, Hugh M0WYE <[email protected]> wrote:
>
> Seems unlikely that the magnetism would reach that far to me - the magnetic
> field would be no different to any other large generating set - they are
> just an ordinary alternator driven through a gearbox.
> If they did affect magnetic compasses you would have thought that the place
> you would really notice it would be around the coast, with small boats
> sailing in amongst them.
> Although they look as if they are turning slowly, they can't do many rpm
> before the tips of the blades go supersonic, as the blades are many 10s of
> metres long.
> Over what distance did you notice the magnetic effect? perhaps I could get
> down to the ones on Romney Marsh, here in Kent and see if they have any
> effect on a compass needle.
>
> The moving blades can affect radio reception for people living nearby,
> although I've not noticed this myself.
>
> 73
> Hugh M0WYE
>
> ----- Original Message -----
> From: mal hamilton
> To: rsgb
> Sent: Thursday, September 22, 2011 5:09 PM
> Subject: LF: Turbine magnets
> Great for LF!!!!!!!!!!!!!
>
> Experience
>
> Driving to Gleneagles in Scotland last weekend my car magnetic compass was
> reading backwards and erratic and I wondered why.
> The hills es mountain tops are covered with WIND TURBINES,  hugh beasts and
> only turning slowly, cannot be producing much electric.
> however thinking about it I have concluded that the strong MAGNETS in the
> turbines must effect a magnetic compass,  possible aeroplanes as well except
> they are flying very high, might also have an influence on GPS frequencies
> and navigation in these areas
> I must say these hugh Monsters strewn all across the Scottish mountain tops
> and countryside spoils the scenery.
>  de Mal/G3KEV
>
>
>
>
>
>



-- 
73 Warren K2ORS
                WD2XGJ
                WD2XSH/23
                WE2XEB/2
                WE2XGR/1