Earth’s magnetic field could FLIP sooner than previously thought and cause trillions of dollars in damage around the world
- When the magnetic poles flip, Earth’s protective magnetic field weakens
- This would wreak havoc on electrical grid, leave surface exposed to radiation
- Researchers found that field reversals can happen more rapidly than thought
Scientists in recent years have predicted that Earth’s magnetic field could be gearing up to ‘flip’ – a shift in which the magnetic south pole would become magnetic north, and vice versa.
Such an event could have catastrophic effects, wreaking havoc on the electric grid and leaving life at the surface exposed to higher amounts of solar radiation.
While it’s previously been thought that these reversals take place at intervals of hundreds of thousands of years, a new study suggests it could happen in just a matter of centuries.
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Scientists in recent years have predicted that Earth’s magnetic field could be gearing up to ‘flip’ – a shift in which the magnetic south pole would become magnetic north, and vice versa. Earth’s magnetic field is illustrated above
Scientists estimate Earth’s North and South magnetic poles flip every 200,000-300,000 years.
But, it’s been roughly 780,000 years since the last such event, causing many to suspect we’re overdue.
When the magnetic poles flip, Earth’s protective magnetic field weakens, leaving its inhabitants at higher risk from the effects of space weather.
‘Earth’s magnetic field, which has existed for at least 3.45 billion years, provides a shield from the direct impact of solar radiation,’ said Professor Roberts from the ANU Research School of Earth Sciences.
‘Even with Earth’s strong magnetic field today, we’re still susceptible to solar storms that can damage our electricity-based society.’
In the new study, researchers at the Australian National University analyzed the paleomagnetic record from 107,000 to 91,000 years ago by analyzing a stalagmite from a cave in southwestern China.
The team conducted magnetic analysis and radiometric dating on the meter-long sample, revealing the behaviour of the ancient magnetic field.
And, they found the magnetic field experienced a rapid shift over the span of about two centuries, decreasing in strength by about 90 percent when a field reversal occurred.
In the new study, researchers at the Australian National University analyzed the paleomagnetic record from 107,000 to 91,000 years ago by analyzing a stalagmite from a cave in southwestern China
WHAT COULD HAPPEN TO EARTH IF ITS POLES FLIPPED?
The Earth’s magnetic field is in a permanent state of change.
Magnetic north drifts around and every few hundred thousand years the polarity flips so a compass would point south instead of north.
The strength of the magnetic field also constantly changes and currently it is showing signs of significant weakening.
Life has existed on the Earth for billions of years, during which there have been many reversals.
There is no obvious correlation between animal extinctions and those reversals. Likewise, reversal patterns do not have any correlation with human development and evolution.
It appears that some animals, such as whales and some birds use Earth’s magnetic field for migration and direction finding.
Since geomagnetic reversal takes a number of thousands of years, they could well adapt to the changing magnetic environment or develop different methods of navigation.
Radiation at ground level would increase, however, with some estimates suggesting that overall exposure to cosmic radiation would double causing more deaths from cancer. ‘But only slightly,’ said Professor Richard Holme.
‘And much less than lying on the beach in Florida for a day. So if it happened, the protection method would probably be to wear a big floppy hat.’
Electric grid collapse from severe solar storms is a major risk. As the magnetic field continues to weaken, scientists are highlighting the importance off-the grid energy systems using renewable energy sources to protect the Earth against a black out.
‘The very highly charged particles can have a deleterious effect on the satellites and astronauts,’ added Dr Mona Kessel, a Magnetosphere discipline scientist at Nasa.
In one area, there is evidence that a flip is already occurring. ‘The increasing strength of the South Atlantic anomaly, an area of weak field over Brazil, is already a problem,’ said Professor Richard Holme.
The Earth’s climate could also change. A recent Danish study has found that the earth’s weather has been significantly affected by the planet’s magnetic field.
They claimed that fluctuations in the number of cosmic rays hitting the atmosphere directly alter the amount of cloud covering the planet.
Henrik Svensmark, a weather scientist at the Danish National Space Centre who led the team behind the research, believes that the planet is experiencing a natural period of low cloud cover due to fewer cosmic rays entering the atmosphere.
The damage to power grids and communications systems resulting from such a flip in today’s society would cause trillions of dollars in damage, the researchers explain.
‘Hopefully such an event is a long way in the future and we can develop future technologies to avoid huge damage, where possible, from such events,’ Professor Roberts said.
The study suggests Earth’s magnetic field is a lot more unpredictable than suspected, the researchers say.
‘The record provides important insights into ancient magnetic field behaviour,’ Professor Roberts said, ‘which has turned out to vary much more rapidly than previously thought.’