What do Agonic Lines indicate?

What do Agonic Lines indicate?

• A. Lines indicating areas with the same magnetic declination.
• B. Lines showing boundaries of time zones.
• C. Are lines indicated where there is no magnetic declination.
• D. Lines that connect major airports.

Answer: (C)

An agonic line is the path where magnetic declination is zero. Magnetic declination is the angle between true north (geographic) and magnetic north. On most of the globe these two norths differ, so a compass needle points to magnetic north, not true north. But along the agonic line, magnetic north aligns with true north, so there is no angular difference. That means a compass reading directly corresponds to true directions along this line. Remember, agonic lines move over time as Earth's magnetic field changes, and they are the special case of zero declination on the broader concept of lines of equal declination (isogons).

An agonic line is the path where magnetic declination is zero. Magnetic declination is the angle between true north (geographic) and magnetic north. On most of the globe these two norths differ, so a compass needle points to magnetic north, not true north. But along the agonic line, magnetic north aligns with true north, so there is no angular difference. That means a compass reading directly corresponds to true directions along this line. Remember, agonic lines move over time as Earth's magnetic field changes, and they are the special case of zero declination on the broader concept of lines of equal declination (isogons).