Independence of Geomagnetic Polarity Intervals

Summary The statistical independence of sequences of geomagnetic polarity intervals has been investigated using correlation analysis to test the hypothesis that reversals are generated by a renewal process. In the analysis, the sequence of Cenozoic geomagnetic reversals as determined from palaeomagnetic studies was first divided into two sub-intervals during which the reversal process was stationary. Within both of these sub-intervals the lengths of successive polarity intervals are statistically independent. The present analysis does not support an earlier interpretation that reversals are generated by a Markov process. Instead they are found to be consistent with generation by a renewal process.