magnetic variation
True. Declination is the angular difference between true north (the direction of the North Pole) and magnetic north (the direction a compass points towards).
The magnetic declination in San Diego, California is approximately 12 degrees east, which means there is a 12 degree difference between true north and magnetic north in that area.
An ordinary magnetic compass points to magnetic north, not to true north. If the difference between the two directions is large and not accounted for, you can get lost.
They would not arrive at the correct location. True north refers to the rotational pole. Compasses point roughly towards the magnetic pole. I say roughly because geographic and man made features can distort the magnetic waves. The rotational and magnetic pole are not at the same place. Most maps are drawn according to the rotational pole (true north).
magnetic variation
magnetic variation
True north relates to what we consider the north pole. However the axis on magnetic terms isn't in the same location. Magnetic north is still north but there is an angle difference between the two.
Magnetic declination or variation.
True. Declination is the angular difference between true north (the direction of the North Pole) and magnetic north (the direction a compass points towards).
It is measured exactly the same in the Southern hemisphere (no difference between the two hemispheres). It is the difference between magnetic north and true north and it varies all over the globe. Magnetic declination (also called magnetic variation) is positive when magnetic north is east of true north (clockwise) and it is negative when magnetic north is west of true north (anti-clockwise).
The magnetic declination in San Diego, California is approximately 12 degrees east, which means there is a 12 degree difference between true north and magnetic north in that area.
Assuming the subject is magnetic declination the difference between the north pole and the true north pole this difference, is the magnetic declination, there is not information on what purpose it serves.
An ordinary magnetic compass points to magnetic north, not to true north. If the difference between the two directions is large and not accounted for, you can get lost.
Geographic north is the direction towards the North Pole, while magnetic north is the direction towards the north-seeking pole of a magnet. The two points do not align perfectly due to the Earth's magnetic field, causing a discrepancy between true north and magnetic north.
the magnetic north pole moves while the geographic north pole stays in the same place
There is a general geographical difference, called magnetic declination. In addition, there may be differences that arise locally, as a result of nearby objects that attract a magnet, which is called magnetic deviation. Related links are given below.