During geomagnetic reversals, which property changes?

During geomagnetic reversals, which property changes?

• A. Inclination
• B. Intensity
• C. Polarity
• D. Direction

Answer: (C)

Geomagnetic reversals flip the polarity of Earth's magnetic field—the sign of the global dipole moment. Imagine the field as a giant bar magnet: polarity is which end points toward the geographic north. In a reversal, that dipole flips, so the end that previously pointed toward the north now points south, and the south end points north. That reversal of polarity is the defining change. The field’s strength (intensity) can dip and the field can become more complex during the transition, and the local direction or inclination at a point may vary, but the hallmark change is the flip in polarity.

Geomagnetic reversals flip the polarity of Earth's magnetic field—the sign of the global dipole moment. Imagine the field as a giant bar magnet: polarity is which end points toward the geographic north. In a reversal, that dipole flips, so the end that previously pointed toward the north now points south, and the south end points north. That reversal of polarity is the defining change. The field’s strength (intensity) can dip and the field can become more complex during the transition, and the local direction or inclination at a point may vary, but the hallmark change is the flip in polarity.