Orienting a map

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Orienting a map means to you are positioning it so its North is actually pointing north. When you orient a map and know where you are on the map, you can look in a certain direction and see a real landmark and find it on the map.

Using a compass

Orienting the map is really easy with just 3 steps:

Example of magnetic declination showing a compass needle with a "positive" (or "easterly") variation from True North. Ng is geographic or true north, Nm is magnetic north, and δ is magnetic declination.
  1. Lay your map out on a relatively flat, smooth surface.
  2. Place the compass flat on the map, lining up with the magnetic north indicator.
  3. Rotate the entire map (with compass) until the map's magnetic north arrow lines up with the compass needle (red north line).

The map should now be oriented to the terrain. If you know where you are on the map, you should be able to look in any direction and see the objects represented on the map in the same direction.

Using landmarks

If you know where you are on your map, you can also orient your map by distant features. If you can see a known mountain in one direction and a lake off another way, then just lay the map out and turn it so the corresponding marks on the map align with the distant features. Your map will then be oriented.

Magnetic declination

Magnetic declination, or magnetic variation, is the angle between magnetic north (the direction the north end of a magnetized compass needle points, corresponding to the direction of the Earth's magnetic field lines) and true north (the direction along a meridian towards the geographic North Pole). This angle varies depending on your position on the Earth's surface and changes over time.

As at 1 March 2019:

  • Magnetic declination in Cape Town, South Africa is -25.36°
  • Magnetic declination in Johannesburg, South Africa is -18.97°
  • Magnetic declination in Durban, South Africa is -25.78°
  • See magnetic-declination.com

See also