The magnetic field of our planet might flip within the next hundred years, suggests new data.
A lot of people were concerned the Earth’s magnetic field would suddenly reverse at the end of the Mayan calendar and though that didn’t happen, there is more information which suggests that this could happen within our children’s lifetime.
What that means is north on a compass would point toward what is now south and vice versa. The new data, collected by scientists from Italy, France, Columbia University and the University of California, Berkeley shows such a shift happened within a 100-year time period around 786,000 years ago. Such a reversal tends to happen after a rapid period of weakening in the magnetic field, which evidence shows we are currently experiencing.
There’s little need to worry. While the scientists who discovered this admit it could affect the electrical grid, they don’t seem concerned. They note that cancer rates could theoretically go up during a period of little to no magnetic field protection from cosmic rays, but the world will not end. “Reversals are the rule, not the exception,” NASA pointed out when discussing the possible event in 2012. Reversals have happened many times in the planet’s history. “A reversal might, however, be good business for magnetic compass manufacturers,” NASA joked.
A magnetic field shift is old news. Around 800,000 years ago, magnetic north hovered over Antarctica and reindeer lived in magnetic south. The poles have flipped several times throughout Earth’s history. Scientists have estimated that a flip cycle starts with the magnetic field weakening over the span of a few thousand years, then the poles flip and the field springs back up to full strength again. However, a new study shows that the last time the Earth’s poles flipped, it only took 100 years for the reversal to happen.
The Earth’s magnetic field is in a weakening stage right now. Data collected this summer by a European Space Agency (ESA) satellite suggests the field is weakening 10 times faster than scientists originally thought. They predicted a flip could come within the next couple thousand years. It turns out that might be a very liberal estimate, scientists now say.
“We don’t know whether the next reversal will occur as suddenly as this one did, but we also don’t know that it won’t,” Paul Renne, director of the Geochronology Center at the University of California, Berkeley, said in a statement.
Geologists still are not sure what causes the planet’s magnetic field to flip direction. Earth’s iron core acts like a giant magnet and generates the magnetic field that envelops the planet. This helps protect against blasts of radiation that erupt from the sun and sometimes hurtle toward Earth. A weakening magnetic field could interrupt power grids and radio communication, and douse the planet in unusually high levels of radiation.
While the ESA satellite studied the magnetic field from above, Renne and a team of researchers studied it from below. The researchers dug through ancient lake sediments exposed at the base of the Apennine Mountains in Italy. Ash layers from long-ago volcanic eruptions are mixed into the sediment. The ash is made of magnetically sensitive minerals that hold traces of Earth’s magnetic field lines, and the researchers were able to measure the direction the field was pointing.
Renne and colleagues then used a technique called argon-argon dating — which works because radioactive potassium-40 decays into argon-40 at a known rate — to determine the age of the rock sediment. The layers built up over a 10,000-year period, and the researchers could pinpoint where the poles flipped in the rock layers. The last flip happened around 786,000 years ago.