When the Earth's magnetic poles flipped out
The Earth's magnetic poles temporarily reversed themselves 42,000 years ago, triggering environmental catastrophe, according to a new study.
Why it matters: The research sheds new light on a period of chaotic climatic change and human upheaval — and provides a warning that the same thing could happen to us.
Driving the news: In a study published Thursday in Science, researchers analyzed the rings found in ancient kauri trees in New Zealand to produce a radiocarbon archive.
- The tree ring data shows that nearly 42,000 years ago, the Earth's geomagnetic field flipped and stayed reversed for some 800 years before returning to normal.
What happened: Scientists knew that the reversal — called the Laschamp Excursion — had happened, but the new study provides a more accurate time frame.
- It also shows just how catastrophic the event likely was for the Earth and those living on it, including humans and their evolutionary cousins the Neanderthals.
- With virtually no protective magnetic field, and with solar activity at an ebb, the planet was bombarded with high-energy particles from outer space, leading to rapid climate change and spectacular electrical storms.
- It would have been "like the end of days," said Chris Turney, an Earth scientist at the University of New South Wales and a lead co-author on the paper, in a statement.
What's next: Earlier research has indicated that the Earth's magnetic north pole has been moving at an accelerating pace, which could presage another reversal.