The Earth's magnetic field could reverse in the near future, potentially causing havoc with compasses, as well as electronic devices. The change could also impact life on Earth, including humans.
A dynamo deep within the center of the planet creates a magnetic field that protects inhabitants of the Earth from potentially dangerous charged particles from space. This magnetic field occasionally flips, on an irregular basis. Geologists and geophysicists are uncertain why this process, which last happened on a long time scale 780,000 years ago, occurs.
Geomagnetic reversals usually take place over the course of between 1,000 and 10,000 years. Roughly 41,000 years ago, a complete reversal occurred, but the change only lasted for around 440 years before the poles once again changed. As the reversals took place, the strength of the magnetic field protecting Earth declined by 95 percent.
University of Maryland researchers are recreating conditions in the laboratory to study what may be happening to the planet.
Swarm, a series of three satellites operated by the European Space Agency (ESA), has recorded a dramatic weakening of the magnetic field over the last six months. The greatest losses are seen over the Western hemisphere, while the cover is strengthening over the southern Indian Ocean. Geologists believe magnetic flips of the poles begin with a loss of strength in the magnetic field, followed by the reversal and rebuilding. Most of the time throughout Earth's history, this appears to have occurred over the course of thousands of years. However, the last change may have happened in as little as 100 years, according to researchers.
"It's amazing how rapidly we see that reversal. The paleomagnetic data are very well done. This is one of the best records we have so far of what happens during a reversal and how quickly these reversals can happen," Courtney Sprain, graduate student at the University of California, Berkely said.
Magnetic north may now be moving toward Siberia, according to data from the fleet of spacecraft. The planet's magnetic field is losing strength ten times faster than predicted.
The magnetic field around our home planet extend 370,000 miles above the Earth, well beyond the orbit of the Moon. Around 800,000 years ago, what we now refer to as magnetic north was located over Antarctica, and the southern pole was located in the Arctic circle.
The effects of a weakened magnetic field are impossible to predict, although the surface of the planet, and the life on it, would be subjected to greater doses of radiation, particularly following solar storms. Earlier reversals of the planetary magnetic field can be seen in layers of rock.
Study of the Swarm data and what it could mean for a potential reversal of the Earth's magnetic field was profiled in Geophysical Journal International.
