Scientists have discovered a remarkable flip in the Earth’s magnetic field that occurred over 40,000 years ago, with new data from the European Space Agency’s Swarm satellite mission revealing its details.
Researchers mapped the so-called Laschamps event by combining satellite data with evidence of magnetic field line movements on Earth. They used natural noises like wood creaking and rock crashing to represent this historic flip in sound waves.
This dramatic change happened when the liquid metals in the planet’s core began to swirl, causing the Earth’s magnetic field to extend tens to hundreds of thousands of kilometers into space. The resulting protection against atmosphere-stripping solar particles was a result of the field’s closed loop formation above and below the surface.
The flip occurred about 41,000 years ago, leaving behind signatures in Laschamps lava flows in France. It weakened the magnetic field to only 5% of its current strength, allowing an influx of cosmic rays into the Earth’s atmosphere. This led to increased levels of beryllium-10 isotopes and higher-than-normal solar bombardment.
The altered atoms formed when cosmic rays reacted with the atmosphere, ionizing the air and damaging the ozone layer. With global climate change being a potential consequence, scientists speculate that this event may have contributed to the extinction of Australia’s megafauna and changes in human cave use.
Understanding these extreme events is crucial for predicting future magnetic field fluctuations, assessing environmental impacts, and mitigating the effects on the Earth system. Researchers used ESA’s Swarm constellation data from 2013 onwards to measure magnetic signals from the core, mantle, crust, oceans, ionosphere, and magnetosphere.
The study provides new insights into the Earth’s magnetic field and its role in protecting our planet.
Source: https://www.sciencealert.com/earths-flipping-magnetic-field-heard-as-sound-is-an-unnerving-horror