Hi, The difference between true meridian and magnetic meridian is called a decimation. It changes from place to place and also affect due to local errors. The difference between horizontal line and magnetic line of field is called as magnetic dip. True north is a fixed point on the earth. Magnetic north is different. It is the direction that a compass needle points towards the alignment of Earth’s magnetic field. Since, its position is contii changing, and again magnetic north and true north will align.

Zack Wheeler
Estates manager