Flip-Flop of Earth’s Magnetic Field Probed
Some 41,000 years ago a complete reversal of the Earth’s magnetic field occurred and compass needles would have pointed south not north, German scientists say. Researchers at the Helmholtz Center Potsdam — GFZ German Research Center for Geosciences report the most remarkable feature of the phenomenon was the speed of the reversal.
“The field geometry of reversed polarity, with field lines pointing into the opposite direction when compared to today’s configuration, lasted for only about 440 years, and it was associated with a field strength that was only one quarter of today’s field,” GFZ researchers Norbert Nowaczyk said. “The actual polarity changes lasted only 250 years. In terms of geological time scales, that is very fast.”