Earth's magnetic north pole is heading for Russia and scientists are puzzled
Unlike its geographic poles, Earth's magnetic poles that serve as the base of our navigation are actively moving.
The north magnetic pole has been gradually moving across the Canadian Arctic toward Russia since 1831. But its swift speed toward Siberia in the last couple of years at a speed of around 34 mph has forced scientists to upgrade the World Magnetic Model. Used by civilian navigation systems, the North Atlantic Treaty Organization, and US and British militaries - a year ahead of schedule.
World Magnetic Model 2020
The World Magnetic Model 2020 forecasts that the rod will continue on its route to Russia. But now the rate is gradually decreasing to approximately 24.8 miles each year. Since its discovery in 1831, the rod has traveled 1,400 miles.
The magnetic field reverses its polarity every several hundred thousand years. Where the magnetic north pole resides in the geographic South Pole. The final reversal took place 770,000 decades back.
In a new study, researchers found that the previous field change took 22,000 years to finish - much longer than expected or anticipated, the researchers said.
Although some think reversals could occur over the course of a human lifetime, the findings do not support that theory.
A worldwide survey of sea sediments
Researchers could study the reversal by assessing a worldwide survey of sea sediments, Antarctic ice cores and lava flows. The details within these samples demonstrated how Earth's magnetic field has diminished, altered partially, stabilized and reversed more than a million decades.
"Reversals are made in the deepest parts of the Earth's interior. But the consequences manifest themselves all the way through the Earth and especially in the Earth's surface and in the air," stated Brad Singer, study author and University of Wisconsin-Madison geologist. "Unless you've got a complete, accurate and high profile record of what a field change is like on the surface of the planet. It's tough to even discuss what the mechanisms of creating a change are."
Our planet's magnetic field is produced by an interaction between the liquid iron outer core spinning around the solid inner core. When a reversal occurs, the typically powerful magnetic field weakens.
The magnetic field
Stone formation acts as a means to monitor the fluctuations in the magnetic field. Lava flows and sediments record the condition of the magnetic field, marking if they were created. Geologists can use the samples such as pieces of a puzzle, reconstructing the history of the magnetic field. The record goes back millions of years, but it is the clearest when looking at the last change.
"Lava flows are perfect recorders of the magnetic field. They have a whole lot of iron-bearing minerals, and if they cool, they lock in the direction of the area," Singer said. "But it is a spotty record. No volcanoes are erupting continuously. So we are relying on careful fieldwork to identify the ideal records."
Radioisotope dating of lava flows and constant magnetic readings from the seafloor and Antarctic ice cores helped recreate an image of the final reversal for the researchers.
Argon can be quantified from the lava flows as the radioactive decay of potassium happens in the stones, while beryllium can be measured in the ice cores. A diminished magnetic field enables more cosmic radiation from space to attack our atmosphere, which generates more beryllium.
The true reversal took less than 4,000 years - a drop in the bucket when compared to Earth's deadline up to now. But leading up to this change were 18,000 decades of uncertainty, including two temporary and partial reversals. This is twice as long as anticipated.
Upcoming reversal
The magnetic field declines in strength about 5 percent every century and signs of weakening in the area point to an upcoming reversal - but it is tough to know when that reversal will take place.
If a change happened during our life, it might impact navigation, communications, and satellites. However, the investigators believe that we'd have generations to accommodate lengthy periods of instability in the magnetic field.
"I have been working on this problem for 25 years," Singer said. "And now we've got a richer record and better-dated record of the previous reversal than previously."
