Researchers from UNSW Sydney released a study that looks at the last major geomagnetic reversal that occurred on Earth about 42,000 years ago. The team says that the Earth’s magnetic field broke down at that time and caused massive and sudden climate change on the planet. All around the world, there were a few centuries of what the team calls apocalyptic conditions triggered by a reversal of the Earth’s magnetic poles combined with the behavior of the sun.
The geomagnetic reversal came with a series of dramatic events that had a significant impact on the planet. During the reversal, the ozone layer was destroyed, electrical storms ravaged tropical areas, solar winds would’ve generated auroras all around the planet, and Arctic air engulfed North America. With the frigid air pouring into North America, ice sheets and glaciers would’ve formed rapidly as weather patterns shifted dramatically.
All life that was present on Earth at the time faced severe trials and tribulations. Researchers believe the event could be what led to the extinction of the Neanderthals and other megafauna and forced modern humans to seek protection in caves. Scientists point out that the magnetic North Pole where a compass needle points doesn’t have a permanent location.
It typically wobbles around very near the geographic North Pole, which is the point around which the Earth spins due to movements of the earth’s core. Scientists don’t exactly understand what can cause magnetic pole movements that are more extreme than wobble, but they are known to happen. The event that happened about 42,000 years ago is known as the Laschamps Excursion.
Scientists used data gathered from inside the rings of ancient trees in New Zealand preserved in peat bogs and other sediments for more than 40,000 years. Information preserved in the rings shows how the atmosphere of the planet changed during this time.