Turn the compass over. Insert the metal key (provided with your compass) into the adjustment screw. Turn the key until the declination indicator is the correct number of degrees east or west of 0° (15.6 degrees West in this example).
What is the cause of magnetic declination?
In a vehicle such as a ship or aircraft, a compass is influenced by the magnetism of the iron used in the construction of the vehicle as well as the Earth’s magnetic field. This causes the compass needle to point in the wrong direction. … The secular variation of the magnetic field causes declination to change with time.
Where is magnetic declination minimum?
However, most locations on Earth have a considerably smaller declination. On the west coast of the United States, the compass direction lies between 10 and 16 degrees east of true north. In locations on the east coast, the magnetic declination is about 10–12 degrees west.
What is current magnetic declination?
Magnetic declination, sometimes called magnetic variation, is the angle between magnetic north and true north. Declination is positive east of true north and negative when west. Magnetic declination changes over time and with location.
Do you add or subtract magnetic declination?
Whenever you transfer a magnetic bearing taken in the field to your map, you add the magnetic declination to get the true bearing. (Note that a west declination is, in essence, subtracted because you are adding a negative number.)
What is the difference between magnetic and true north?
True north is a fixed point on the globe. Magnetic north is quite different. Magnetic north is the direction that a compass needle points to as it aligns with the Earth’s magnetic field. What is interesting is that the magnetic North Pole shifts and changes over time in response to changes in the Earth’s magnetic core.
How much does magnetic declination change per year?
The magnetic declination in a given area may (most likely will) change slowly over time, possibly as little as 2–2.5 degrees every hundred years or so, depending upon how far from the magnetic poles it is. For a location closer to the pole like Ivujivik, the declination may change by 1 degree every three years.
Why is it important to correct magnetic declination?
Magnetic declination is an important concept for accurate navigation. A compass will always point along the lines of magnetic force (which converge on what are called the magnetic poles). … As the earth’s magnetic field varies over time, the positions of the north and south magnetic poles gradually change.
Does declination mean decline?
Look at the noun declination and you can see the verb decline, which means “to lessen,” “to slope down,” and “to refuse.” Declination is the process of doing any of these things. … In astronomy, it’s also the distance between an object and the celestial equator, measured at an angle.
What does a declination of 0 mean?
Declination, in astronomy, the angular distance of a body north or south of the celestial equator. … North declination is considered positive and south, negative. Thus, +90° declination marks the north celestial pole, 0° the celestial equator, and -90° the south celestial pole.
Are there places on Earth where magnetic declination equals 0?
Earth is like a giant magnet with a North and South Pole. However, the magnetic North and South Pole are not aligned with the Geographic North and South Pole. … The green line is where the declination equals zero and the direction of True North and Magnetic North are equal (agonic line).
How many hours of declination exist on earth?
The total range of right ascension is 24 hrs = 360 deg / 15 deg/hr. The 15 deg/hr conversion factor arises from the rotation rate of the Earth. Declination is analogous to latitude and is measured as north or south of the celestial equator.
How many degrees off is magnetic north?
Depending on where you are, the angle between true north and magnetic north is different. In the U.S., the angle of declination varies from about 20 degrees west in Maine to about 21 degrees east in Washington. (See Figure 6.7).
How do you find magnetic variation?
Variation is the difference in degrees and minutes between True North on the chart you are looking at and Magnetic North at that place at a given time. You can then apply the rate of variation every year to find variation at that location in any given year.