Here is a fascinating article – it shows how there is evidence of magnetic reversals “frozen” within the layers of rock. But what this article focuses on is research on a very small volcanic rock layer that based on its size could have only cooled (from lava) and formed within 15 days. What is significant is that it shows the complete magnetic reversal from the volcanic layer below and the volcanic layer above. This shows that it doesn’t take thousands of years for the magnetic field to reverse which happens over and over again over millions of years, but it shows that at that point in earth history it happened really fast – likely as some catastrophic event was happening (a worldwide flood and rapid plate tectonics).
This is yet another physical evidence that fits a catastrophic flood thousands of years ago better than billion year old slow changes to Earth history!