Researchers at a number of institutions around the globe have stumbled on a hint that the mantle does leave its mark on magnetic reversals. They have found that as the poles wander from north to south or vice versa during successive reversals, they show a startling tendency to trace out the same paths across the surface of the planet.
This process has persisted for millions of years, through reversal after reversal, researchers have realized. They feel, this could only happen with the help of the mantle. The precise connection between mantle and core is far from clear, but if proven and understood it may shed light on the larger mystery of why reversals happen in the first place.
Bradford Clement of Florida International University declared it was and “astonishing thing” to find that the poles actually tend to follow one of two well worn paths. One leads through North and South America and the other less heavily travelled path, stretches across eastern Asia and Australia. The only way they can explain this is the despite its short memory, the core seams to recall where its magnetic poles should go during reversals hundreds of thousands or even millions of years apart.
Kerr, R. (1991). A Core-Mantle Link? Science, 252(5013), 1617-1618