Regions of the sea floor with negative magnetic anomalies were formed during times when the Earth's magnetic field
A) was exceptionally strong.
B) was exceptionally weak.
C) had normal polarity.
D) had reversed polarity.

Question

Quizplus · Accepted Answer

Regions of the sea floor with negative magnetic anomalies were formed during times when the Earth's magnetic field had reversed polarity. This is because the magnetized minerals in the rocks align themselves with the Earth's magnetic field at the time of their formation. When the polarity of the Earth's magnetic field reverses, the orientation of these minerals also reverses, resulting in a negative magnetic anomaly in the sea floor.

Regions of the Sea Floor with Negative Magnetic Anomalies Were