The planet’s magnetic field is up to mischief again and geologists are pretty dumbfounded.
Earth’s magnetic poles can wander several kilometers every year, however, the north pole’s movement has become increasingly stranger in recent years. For reasons that are currently unclear, the magnetic north pole seems to be increasingly slipping away from Canada and towards Siberia at an erratic rate, according to a news report in Nature.
“The location of the north magnetic pole appears to be governed by two large-scale patches of magnetic field, one beneath Canada and one beneath Siberia,” Phil Livermore, a geomagnetist at the University of Leeds in the UK said at the latest American Geophysical Union meeting, according to Nature.
“The Siberian patch is winning the competition.”
Every five years, the National Oceanic and Atmospheric Administration (NOAA) maps out the Earth’s magnetic field in the World Magnetic Model (WMM). This was last published in 2015, with the next edition planned for 2020, but this freak behavior forced scientists to revise the map earlier than anticipated. Unfortunately, the revamped WMM was supposed to be released on January 15, but it’s been postponed until at least January 30 due to the ongoing government shutdown.
Earth’s magnetic field is created by molten iron in its core swirling around through convection currents. It’s a fairly chaotic situation in there, resulting in a complex pattern of magnetism which can prove extremely difficult to model and predict. Just to make things even more complicated, an unusually punchy geomagnetic pulse occurred under South America in 2016, which is believed to have contributed to the recent unexpected changes.
However, it largely remains unclear why the magnetic field beneath Canada is appearing to weaken in such a strange way.
You might be wondering whether any of this matters. Well, the magnetic field is central to many forms of navigation. Most obviously, a compass relies on magnetic fields, but more advanced systems of navigation use the field as a bearing too. These currently anomalies shouldn’t be strong enough to completely screw this up, however, it’s most certainly something geologists need to keep on top of.
Indeed, it is possible for truly monstrous changes to the magnetic field to take place. Scientists know the Earth can undergo a phenomenon known as a “geomagnetic reversal”, where these magnetic poles literally switch sides. The last time this happened was 781,000 years ago, but it’s believed to have occurred every 20,000-30,000 years over the last 20 million years (although there have been exceptions).
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