Jeff Morris wrote:

"The_navigator©" wrote in message
...
...

Closer to the poles, the magnetism
of the Earth pulls either the north or south pole
of the compass down more. Close to the equator,
the force is almost parallel.

Not really, the region of zero dip wanders about 12 degrees north and
south of the equator. Check out Chart 30 for this info?


He was refering to the Magnetic Equator.


Not as I read it he wasn't.


You may be thinking about variation, which is
definitely affected by local magnetic anomalies
like massive iron deposits.

Dip is also affect by anolmalies.


Dip and variation are the same phenomenon, measured on different axis.

What is the phenomenon you have in mind?

Cheers MC