This story is at https://phys.org/news/2026-03-laschamps-geomagnetic-excursion-today-aviation.html … Finnish scientists have been looking at how a geomagnetic excursion event might affect flights from Helsinki airport. I would have thought that would have been the last of the problems they should worry about. However, it then seemed to come up with some definite dating on the duration of the Laschamp event, and what it involved. A reduction of the magnetic field intensity to 5 per cent of what it is in the modern world. It then said it took 5000 years for a full recovery of that field strength. In early reports on Laschamp there was quite a different set of numbers – derived from volcanic rocks in the Laschamp region of France. Nowadays, they have sediment cores and ice cores in support of their dates – and the much vaunted Kauri trees of New Zealand. Even loess layering has come to the aid of the dating lobby.
We are also told there was multi-polar magnetic poles in subtropical and temperate regions of the world. The weakening of the magnetic pole at the north led to the creation of these other minor poles. For information on this I recommend reading Marinus Anthony van der Sluijs, ‘On the Origin of Myths‘ volume 2 [Vancouver, 2021} which is extremely informative on the formation of multi poles – and the subject in general. This was reviewed in C&C Review 2021:3 and is available on our web site. It is a fascinating subject which is in early days as far as understanding the process fully.
The magnetic field protects Earth from harmful radiation with an origin in space. The solar wind, for example, and cosmic rays from outside our solar system. A weakening, or magnetic reversal, opens the Earth to that radiation – with unknown consequences for life on Earth. Calculations made by the Finnish research team show that cosmic radiation penetrated the atmosphere at record levels during the Laschamp event. The magnetic field became irregular, directing cosmic particles in unexpected ways. However, the researchers say there was no actual reversal, but instead, it weakened – and is described as an excursion [the geomagnetic field going on walkies]. I thought I had read there was a definite reversal but it reinstated its former position after a short period where the south pole became the north pole, and vice versa. Hence, I was intrigued and had a brief look on the internet to see what the position was now, as perhaps it had changed.
The wiki says, https://en.wikipedia.org/wiki/Laschamp_event … that a reversed field lasted for just 250 years, while the magnetic field remained reversed for approximately 440 years. Earth’s magnetic field declined to 5 per cent of its normal strengeth – and was 25 per cent the strength when fully reversed. At https://www.sciencealert.com/earth-s-magnetic-field-flipped-42-000-years-ago-with-dramatic-consequences … where the event is said to have lasted 800 years [in 2021]. However, back in 2012 at https://www.sciencedaily.com/releases/2012/10/121016084936.htm …. since 44,000 years ago, a complete and rapid reversal of the magnetic field occurred. Sediment cores from the Black Sea show that in this period a compass would have pointed south rather than north – but again we have the number of 440 years plus 250 years as per the wiki. It is definite that a full reversal occurred – and compasses pointed towards the south pole rather than the north pole. At https://www.sciencedirect.com/science/article/abs/pii/S0012821X0400562X … we have an article with the title ‘On the Origin of Laschamp Geomagnetic Excursion’ [2004]. See also for the full article https://doi.org/10.1016/j.epsl.2004.09.018 … on how the date was arrived at. but see also https://doi.org/10.1016/j.quascirev.2010.01.010 … where the author says there is a link between the Neanderthal extinction and the Laschamp event.