Rapid Magnetic Field Reversal May Leave Earth More Sun-exposed
A study on past reversals of Earth’s magnetic field has found that a shift could occur 30 times faster than previously thought. A magnetic shift event could increase our exposure to the Sun’s radiation. Some claim power grids and satellites could fail massively which may cause trillions of dollars in power and communications systems damage.
the churning of liquid material (magma within the earth’s interior provides the Earth’s magnetic field. A change in the direction of movement of this liquid matter would change the direction of the poles. (whereby the magnetic south pole became the magnetic north pole and vice versa) A phenomenon called Magnetic field reversal.
Professor Andrew Roberts from The Australian National University (ANU) said the magnetic field’s strength decreased by about 90 percent when a field reversal occurred, making the Earth much more vulnerable to the Sun’s radiation.
“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 who was part of the study led by Distinguished Professor Chuan-Chou Shen at the National Taiwan University and lead author Dr. Yu-Min Chou of the Southern University of Science and Technology in China.
“Even with Earth’s strong magnetic field today, we’re still susceptible to solar storms that can damage our electricity-based society.”
A field reversal would have much more of an effect than the solar storm that hit Earth in 1859. A similar magnitude solar storm today would cause major damage to power grids and communications systems worth trillions of dollars.
The researchers said they have several reasons why the reversal could happen faster than expected
The earths magnetic field is currently 10% weaker than when recording started 175 years ago.
A switch is well overdue. A switch naturally happens 200000 to 300000 years but the last one was 780000 years ago.
“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.
Reference: “Multidecadally Resolved Polarity Oscillations During a Geomagnetic Excursion,” Yu-Min Chou et al., 2018 Aug. 20, Proceedings of the National Academy of Sciences of the United States of America [https://doi.org/10.1073/pnas.1720404115].