Magnetic reversals of the Earth's field have occurred on the average every 200,000 years over the past 5 million years. When was the last magnetic reversal?
A) about 200,000 years ago
B) 1792
C) about 990,000 years ago
D) about 780,000 years ago

Question

Quizplus · Accepted Answer

The last magnetic reversal, known as the Brunhes-Matuyama reversal, occurred approximately 780,000 years ago.

Magnetic Reversals of the Earth's Field Have Occurred on the Average