East may be east, and west may be west but north is not always north. The understanding of this can be the difference between life and death if you are trying to find your way through the wilderness using a compass.  There are in fact two norths; True North and Magnetic North.

True North is what we refer to as the North Pole, the point where the earth’s axis of rotation intersects the earths surface in the northern hemisphere.  Meridians of Longitude converge at the North Pole so the true north arrow on a map is pointing in the same direction as the Meridians of Longitude.

Magnetic North is the direct indicated by the north arrow on a compass. However, the magnetic polarity of the earth does not line up with the rotational axis of the earth.  Magnetic North is in Canada, located on Ellef Ringnes  Island in the Territory of Nunavut (see map below).  Depending on where you are in relationship to Ellef Ringnes Island, the difference between True North and Magnetic North could be quite large.  If you were standing on the 105 degrees west Meridian of Longitude in Saskatchewan, true north and magnetic north would be identical.  If, on the other hand , you were standing on Axel Heiberg Island (east of Ellef Ringnes Island) then Magnetic North would be to the west and likewise your compass would be pointing west.  In Newmarket your compass points roughly 11.5 degrees west of True North (see below)

  The discrepancy (referred to as declination) between True North and Magnetic North is shown on topographic maps by the arrows and the angle is noted in degrees and minutes.  The difference between Magnetic North and Grid North can be determined by either adding or subtracting (whichever is appropriate for the situation) the two angles of declination.  This is very important to understand if you are using both a compass and a map for direction.

  To complicate matters more, Magnetic North is not fixed.  It moves slowly around in the Canadian Arctic.  As a result, the angle of declination between Magnetic North and True North changes over time.  To determine a more accurate measure of the declination you must apply a correction.  The correction is determined by multiplying the annual change (noted on the map below the north arrow) by the number of years that have passed since the map was produced.  This correction is either added or subtracted from the declination as noted on the map.  (Increasing or decreasing)

North Arrow on the Newmarket Topographic Map

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