Magnetism & Compasses

Question 1

Define True North

Answer 1

True north is the direction that points directly towards the geographic North Pole.

True North is a fixed point on the Earth’s globe.

Question 2

Define Magnetic North

Answer 2

Magnetic north is the direction that a compass needle points to as it aligns with the Earth’s magnetic field.

The Magnetic North Pole shifts and changes over time in response to changes in the Earth’s magnetic core.

Magnetic North is not a fixed point.

Question 3

Define Variation

Answer 3

Magnetic variation, is the angle between magnetic north and true north.

Question 4

What is another name for Magnetic Variation?

Answer 4

Magnetic Declination

Question 5

Where is declination positive and negative?

Answer 5

Declination is positive east of true north and negative when west.

Question 6

Define Deviation

Answer 6

Deviation is the angle between Magnetic North and Compass North.

Question 7

What is an Isogonal?

Answer 7

Line across a map points of equal variation.

Question 8

How is variation depicted on Maps and Charts?

Answer 8

Marginal Diagram
Isogonal
Statement of Words
Double Compass rose

Question 9

If using CDMVT, am I adding or subtracting in the direction of the arrows?

Answer 9

Adding