The Frequency and Duration of Reversals

The frequency of geomagnetic reversals is irregular. During certain periods, reversals seem to happen more frequently, while in other periods, the magnetic field may remain stable for tens of millions of years. For example, the average interval between reversals over the last 20 million years has been roughly 200,000 to 300,000 years.

The duration of a geomagnetic reversal is also variable. It can take anywhere from several thousand years to over a million years to complete the flip. The process is not instantaneous but occurs gradually over time.