Magnetism & Compasses Flashcards
Define True North
True north is the direction that points directly towards the geographic North Pole.
True North is a fixed point on the Earth’s globe.
Define Magnetic North
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.
Define Variation
Magnetic variation, is the angle between magnetic north and true north.
What is another name for Magnetic Variation?
Magnetic Declination
Where is declination positive and negative?
Declination is positive east of true north and negative when west.
Define Deviation
Deviation is the angle between Magnetic North and Compass North.
What is an Isogonal?
Line across a map points of equal variation.
How is variation depicted on Maps and Charts?
Marginal Diagram
Isogonal
Statement of Words
Double Compass rose
If using CDMVT, am I adding or subtracting in the direction of the arrows?
Adding