A compass is an instrument that indicates direction, used by mariners, aviators, campers, hunters, and other travelers to enable them to get from one place to another.
In a magnetic compass, directions are obtained by means of one or more magnetic needles pointing in the general direction of the magnetic North Pole under the influence of the magnetic field of the earth.
Did you know that the needle of the compass points to the magnetic north and not the geographical North Pole?
The gyrocompass, which is unaffected by the magnetism of the earth, consists of a gyroscope, with the spinning wheel on an axis confined to the horizontal plane so that its axle aligns itself with the north-south line parallel to the axis of the rotation of the earth, thereby indicating true north.
Contrary to the popular belief, the bobbing needle on a compass does not point to the North Pole at the top of our planet. Instead , the magnetized needle of every compass points to a spot on the map just off the northern coast of Bathurst Island at 76.5 degrees north latitude in the Canadian High Arctic. This invisible spot, known as the magnetic North Pole, is actually 965 miles (1550 km) south of the geographic North Pole.
To make the situation even more interesting, the position of the magnetic pole wanders just a little each year, a phenomenon known as polar wandering. The direction of wandering has been observed to reverse. During geologic history the polarity of the earth’s magnetic field has periodically reversed. When it was first discovered in 1831 the magnetic north pole was 465 miles farther south than it is today.
For these reasons, using a compass in the arctic requires very good navigational skills. Today, people are fortunate in that a technology known as GPS (Global Positioning System) is an affordable and an easy to use tool. By locating 3 or more satellites in orbit, it can pinpoint your location to within 200 yards. One drawback to GPS units is that they run on batteries, which in the extreme cold weather do not function very well. So it is wise that you know how to navigate with a compass as a back up.
How to use a compass...