Application of the local magnetic variation to the recorded heading will give the true heading.

He took the "lay" of the place with a pocket-compass, allowing two seconds for magnetic variation.

The fossil record shows that some organisms respond to profound magnetic variations, but many do not.

In December 2011 the runway numbers will change to 8/26 and 14/32 due to magnetic variation.

On these charts he set down lines connecting those localities at which the magnetic variation was identical.

He also made observations on the magnetic variation of the compass.

Manifestations of upper atmospheric electric currents are the corresponding magnetic variations on the ground.

On April 9th 2013, the runway heading changed from 01/19 to 02/20 due to magnetic variation.

Called magnetic variation when a distinction is needed to prevent possible ambiguity.

On land, magnetic variations are very irregular, and anyway there are many physical features to act as a guide.