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6.4 Direction on the Earth
Direction is defined as
- a point to or from which a person or thing moves or faces.
Bearing is defined as
- the horizontal angle between
- an object's direction and
- the direction to another object.
6.4.2 Describe the 360º Method of Indicating Direction.
For precise navigation purposes, we use
- a circle,
- divide it into 360 degrees with
- North at the top of the circle.
North can be referred to as
- 000° or
All directions are measured clockwise from North, which are then expressed in the form of a three figure group.
- 045° (northeast),
- 180° (south),
- 345° (northwest) and so on.
6.4.4 Describe the Earth's Magnetic Field.
- The earth acts as a huge magnet, and its lines of magnetic force are sufficiently strong to influence the direction of a freely suspended magnetic needle.
- The poles of the magnet earth are known as the north magnetic pole and the south magnetic pole.
- The location of the North Magnetic Pole is in the Hudson's Bay area in Canada, and the South Magnetic Pole is near South Victoria land in Antarctica.
- The lines of magnetic force joining these two poles run roughly north-south.
- A freely suspended magnet will swing so that its axis will align itself in a general north-south direction, with the end called the north-seeking pole pointing to the earth's north magnetic pole.
- The actual direction now shown by the magnet is called magnetic north, and this is the datum used to measure magnetic direction.
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