William sent in a link to https://www.msn.com/em-us/news/technology/scientists-left-confused-after-uncovering-ancient-rocks-that-hold-proof-of-the-earth-s-magnetic-field/ss-BB1oJOXk …. but see also https://www.space.com/earth-ancient-magnetic-field-puzzle-isua …. Rocks that have been dated to 3.7 billion years ago, on the geochronology time scale, display evidence of a strong magnetic field – back then. Scientists are not sure where that magnetic field may have come from. According to the rocks the earth’s magnetic field has not changed much – if at all. Geologists, apparently, do not understand how earth could have produced a magnetic field so early. The evidence is indisputable – as a result of the discovery of zircons, mineral crystals. We are then told the earth’s magnetic field is produced by the dynamo effect generated by electrical currents in the molten outer core. The problem the mainstream consensus has revolves around when the inner core cooled enough to solidify – which is thought to have occurred around 1 billion years ago. The new evidence would seem to rebuff the consensus – but see also https://www.ox.ac.uk/news/2024-04-24-researchers-find-oldest-undisputed-evidence-earth-s-magnetic-field-0 … which informs us the Isua Supracrustal Belt has a unique geology, sitting on top of thick continental crust which protects it from extensive tectonic activity and deformation. This allowed the researchers to build a clear body of evidence supporing the existence of the magnetic field that long ago. Not only that these rocks have not been significantly heated since 3.7 billion years ago and they have also been scraped clean by the Greenland ice sheet.
At https://www.sciencealert.com/extreme-solar-blasts-and-a-weak-magnetic-field-are-a-deadly-combination-for-earth … which seems to contradict some of the above. The powerful aurora in early May illustrated how the solar wind can impact the earth. Occasionally te sun does something even more powerful – and destructive. An extreme solar particle event. Earth’s magnetic shield is critical in its ability to ward off electrically charged solar radiation. The vertical orientation of the poles allows some ionising cosmic radiation to penetrate the upper atmosphere – but see the Bob Johnson videos on this web site for more information on how it works. The incoming radiation interacts with the atmospheric gas molecules in the atmosphere and creates the auroral glow. The thrust of the article is that in recent years the earth’s magnetic field has weakened – and this has occurred on several occasions in the known past. The last major solar event was in AD933 – and the one before was in AD776. It is thought. We are then told solar particle events can deplete ozone in earth’s atmosphere – or alternatively, disperses ozone from the poles towards the temperate and tropical zones. It is of course depleted at the poles, in either scenario – the so called ozone hole, which comes and goes with solar activity ups and downs. Obviously, a really big solar event that breaches the magnetic shield would cause even more disruption of the ozone in the upper atmosphere. This is the destructive bit – which suggests life on earth has adjusted to a certain amount of radiation over the course of time. Interestingly, they say the ozone depletion event only lasts 6 years. During this time earth is subject to increased Ultra Violet levels and can instigate solar induced DNA damage. Or mutations, perhaps. The authors point a finger at the Laschamp Event 42,000 years ago, which included a temporary reversal of earth’s magnetic field. This would be the most recent very big solar whammy. The Gothenburg event at the end of the Ice Age is mostly ignored by mainstream – and is rarely mentioned in polite circles. It is interesting that some researchers have blamed the solar event coinciding with Laschamp as responsible for a mass die of animal life on earth. It also witnessed the disappearance of Neanderthals and Denisovans and was followed by the appearance of modern humans in Eurasia. This is a fascinating study as they go on to link these big solar events to biological changes – in earth history.